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Re: [Dle-develop] [PATCH] efivar: Disable get_next_variable when firmware is broken

[Mike W. <mi...@go...>]

On Tue, Mar 19, 2013 at 2:17 PM, Seiji Aguchi <sei...@hd...> wrote:
>
> [Problem]
> Some firmware implementations return the same variable name on multiple calls to
> get_next_variable().
> In this case, an efivar driver gets stuck in a infinite loop at initializing time,
> register_efivars().
> It is hard for users to fix the broken firmware.
>
> Here is an actual result of the case above.
> http://article.gmane.org/gmane.linux.kernel.efi/835
>
> [Solution]
> This patch terminates the loop immediately and disables get_next_variable()
> at the initializing time when the same variable name is found on multiple
> calls to get_next_variable().
>
> Also, to avoid stucking in the infinite loop,
> update_sysfs_entries returns without calling get_next_variable if the case above happens.
>
> Reported-by: Andre Heider <a.h...@gm...>
> Reported-by: Lingzhu Xiang <lx...@re...>
> Signed-off-by: Matt Fleming <mat...@in...>
> Signed-off-by: Seiji Aguchi <sei...@hd...>
> ---
>  drivers/firmware/efivars.c     |   34 ++++++++++++++++++++++++++++++++--
>  drivers/firmware/google/gsmi.c |    4 +++-
>  include/linux/efi.h            |    3 ++-
>  3 files changed, 37 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c
> index fe62aa3..fa601c6 100644
> --- a/drivers/firmware/efivars.c
> +++ b/drivers/firmware/efivars.c
> @@ -1725,6 +1725,14 @@ static void efivar_update_sysfs_entries(struct work_struct *work)
>         efi_status_t status = EFI_NOT_FOUND;
>         bool found;
>
> +       spin_lock_irq(&efivars->lock);
> +       if (!efivars->ops->get_next_variable) {
> +                       spin_unlock_irq(&efivars->lock);
> +                       pr_warn("efivars: Skip updating sysfs entries\n");
> +                       return;
> +       }
> +       spin_unlock_irq(&efivars->lock);
> +
>         /* Add new sysfs entries */
>         while (1) {
>                 variable_name = kzalloc(variable_name_size, GFP_KERNEL);
> @@ -1960,7 +1968,8 @@ EXPORT_SYMBOL_GPL(unregister_efivars);
>
>  int register_efivars(struct efivars *efivars,
>                      const struct efivar_operations *ops,
> -                    struct kobject *parent_kobj)
> +                    struct kobject *parent_kobj,
> +                    bool *get_next_variable_cannot_call)
>  {
>         efi_status_t status = EFI_NOT_FOUND;
>         efi_guid_t vendor_guid;
> @@ -2006,6 +2015,21 @@ int register_efivars(struct efivars *efivars,
>                                                 &vendor_guid);
>                 switch (status) {
>                 case EFI_SUCCESS:
> +                       /*
> +                        * Some firmware implementations return the
> +                        * same variable name on multiple calls to
> +                        * get_next_variable(). Terminate the loop
> +                        * immediately as there is no guarantee that
> +                        * we'll ever see a different variable name,
> +                        * and may end up looping here forever.
> +                        */
> +                       if (variable_is_present(variable_name, &vendor_guid)) {
> +                               pr_warn("efivars: duplicate variable name.\n");
> +                               *get_next_variable_cannot_call = true;
> +                               status = EFI_NOT_FOUND;
> +                               break;
> +                       }
> +
>                         efivar_create_sysfs_entry(efivars,
>                                                   variable_name_size,
>                                                   variable_name,
> @@ -2056,6 +2080,7 @@ static int __init
>  efivars_init(void)
>  {
>         int error = 0;
> +       bool get_next_variable_cannot_call = false;
>
>         printk(KERN_INFO "EFI Variables Facility v%s %s\n", EFIVARS_VERSION,
>                EFIVARS_DATE);
> @@ -2075,7 +2100,12 @@ efivars_init(void)
>         ops.get_next_variable = efi.get_next_variable;
>         ops.query_variable_info = efi.query_variable_info;
>
> -       error = register_efivars(&__efivars, &ops, efi_kobj);
> +       error = register_efivars(&__efivars, &ops, efi_kobj,
> +                                &get_next_variable_cannot_call);
> +       if (get_next_variable_cannot_call) {
> +               pr_warn("efivars: Disable get_next_variable service\n");
> +               ops.get_next_variable = NULL;

I don't like this pattern of clearing out ops fields.  Can you instead
just add a flag in efivars that is checked before calling
ops->get_next_variable?

> +       }
>         if (error)
>                 goto err_put;
>
> diff --git a/drivers/firmware/google/gsmi.c b/drivers/firmware/google/gsmi.c
> index 91ddf0f..0c205c8 100644
> --- a/drivers/firmware/google/gsmi.c
> +++ b/drivers/firmware/google/gsmi.c
> @@ -778,6 +778,7 @@ static __init int gsmi_init(void)
>  {
>         unsigned long flags;
>         int ret;
> +       bool get_next_variable_cannot_call = false;
>
>         ret = gsmi_system_valid();
>         if (ret)
> @@ -893,7 +894,8 @@ static __init int gsmi_init(void)
>                 goto out_remove_bin_file;
>         }
>
> -       ret = register_efivars(&efivars, &efivar_ops, gsmi_kobj);
> +       ret = register_efivars(&efivars, &efivar_ops, gsmi_kobj,
> +                              &get_next_variable_cannot_call);
>         if (ret) {
>                 printk(KERN_INFO "gsmi: Failed to register efivars\n");
>                 goto out_remove_sysfs_files;
> diff --git a/include/linux/efi.h b/include/linux/efi.h
> index 9bf2f1f..9db51b1 100644
> --- a/include/linux/efi.h
> +++ b/include/linux/efi.h
> @@ -756,7 +756,8 @@ struct efivars {
>
>  int register_efivars(struct efivars *efivars,
>                      const struct efivar_operations *ops,
> -                    struct kobject *parent_kobj);
> +                    struct kobject *parent_kobj,
> +                    bool *get_next_variable_cannot_call);
>  void unregister_efivars(struct efivars *efivars);
>
>  #endif /* CONFIG_EFI_VARS */
> -- 1.7.1

[Dle-develop] [PATCH] efivar: Disable get_next_variable when firmware is broken

[Seiji A. <sei...@hd...>]

[Problem]
Some firmware implementations return the same variable name on multiple calls to
get_next_variable().
In this case, an efivar driver gets stuck in a infinite loop at initializing time, 
register_efivars().
It is hard for users to fix the broken firmware.

Here is an actual result of the case above.
http://article.gmane.org/gmane.linux.kernel.efi/835

[Solution]
This patch terminates the loop immediately and disables get_next_variable()
at the initializing time when the same variable name is found on multiple 
calls to get_next_variable().

Also, to avoid stucking in the infinite loop,
update_sysfs_entries returns without calling get_next_variable if the case above happens.

Reported-by: Andre Heider <a.h...@gm...>
Reported-by: Lingzhu Xiang <lx...@re...>
Signed-off-by: Matt Fleming <mat...@in...>
Signed-off-by: Seiji Aguchi <sei...@hd...>
---
 drivers/firmware/efivars.c     |   34 ++++++++++++++++++++++++++++++++--
 drivers/firmware/google/gsmi.c |    4 +++-
 include/linux/efi.h            |    3 ++-
 3 files changed, 37 insertions(+), 4 deletions(-)

diff --git a/drivers/firmware/efivars.c b/drivers/firmware/efivars.c
index fe62aa3..fa601c6 100644
--- a/drivers/firmware/efivars.c
+++ b/drivers/firmware/efivars.c
@@ -1725,6 +1725,14 @@ static void efivar_update_sysfs_entries(struct work_struct *work)
 	efi_status_t status = EFI_NOT_FOUND;
 	bool found;
 
+	spin_lock_irq(&efivars->lock);
+	if (!efivars->ops->get_next_variable) {
+			spin_unlock_irq(&efivars->lock);
+			pr_warn("efivars: Skip updating sysfs entries\n");
+			return;
+	}
+	spin_unlock_irq(&efivars->lock);
+
 	/* Add new sysfs entries */
 	while (1) {
 		variable_name = kzalloc(variable_name_size, GFP_KERNEL);
@@ -1960,7 +1968,8 @@ EXPORT_SYMBOL_GPL(unregister_efivars);
 
 int register_efivars(struct efivars *efivars,
 		     const struct efivar_operations *ops,
-		     struct kobject *parent_kobj)
+		     struct kobject *parent_kobj,
+		     bool *get_next_variable_cannot_call)
 {
 	efi_status_t status = EFI_NOT_FOUND;
 	efi_guid_t vendor_guid;
@@ -2006,6 +2015,21 @@ int register_efivars(struct efivars *efivars,
 						&vendor_guid);
 		switch (status) {
 		case EFI_SUCCESS:
+			/*
+			 * Some firmware implementations return the
+			 * same variable name on multiple calls to
+			 * get_next_variable(). Terminate the loop
+			 * immediately as there is no guarantee that
+			 * we'll ever see a different variable name,
+			 * and may end up looping here forever.
+			 */
+			if (variable_is_present(variable_name, &vendor_guid)) {
+				pr_warn("efivars: duplicate variable name.\n");
+				*get_next_variable_cannot_call = true;
+				status = EFI_NOT_FOUND;
+				break;
+			}
+
 			efivar_create_sysfs_entry(efivars,
 						  variable_name_size,
 						  variable_name,
@@ -2056,6 +2080,7 @@ static int __init
 efivars_init(void)
 {
 	int error = 0;
+	bool get_next_variable_cannot_call = false;
 
 	printk(KERN_INFO "EFI Variables Facility v%s %s\n", EFIVARS_VERSION,
 	       EFIVARS_DATE);
@@ -2075,7 +2100,12 @@ efivars_init(void)
 	ops.get_next_variable = efi.get_next_variable;
 	ops.query_variable_info = efi.query_variable_info;
 
-	error = register_efivars(&__efivars, &ops, efi_kobj);
+	error = register_efivars(&__efivars, &ops, efi_kobj,
+				 &get_next_variable_cannot_call);
+	if (get_next_variable_cannot_call) {
+		pr_warn("efivars: Disable get_next_variable service\n");
+		ops.get_next_variable = NULL;
+	}
 	if (error)
 		goto err_put;
 
diff --git a/drivers/firmware/google/gsmi.c b/drivers/firmware/google/gsmi.c
index 91ddf0f..0c205c8 100644
--- a/drivers/firmware/google/gsmi.c
+++ b/drivers/firmware/google/gsmi.c
@@ -778,6 +778,7 @@ static __init int gsmi_init(void)
 {
 	unsigned long flags;
 	int ret;
+	bool get_next_variable_cannot_call = false;
 
 	ret = gsmi_system_valid();
 	if (ret)
@@ -893,7 +894,8 @@ static __init int gsmi_init(void)
 		goto out_remove_bin_file;
 	}
 
-	ret = register_efivars(&efivars, &efivar_ops, gsmi_kobj);
+	ret = register_efivars(&efivars, &efivar_ops, gsmi_kobj,
+			       &get_next_variable_cannot_call);
 	if (ret) {
 		printk(KERN_INFO "gsmi: Failed to register efivars\n");
 		goto out_remove_sysfs_files;
diff --git a/include/linux/efi.h b/include/linux/efi.h
index 9bf2f1f..9db51b1 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -756,7 +756,8 @@ struct efivars {
 
 int register_efivars(struct efivars *efivars,
 		     const struct efivar_operations *ops,
-		     struct kobject *parent_kobj);
+		     struct kobject *parent_kobj,
+		     bool *get_next_variable_cannot_call);
 void unregister_efivars(struct efivars *efivars);
 
 #endif /* CONFIG_EFI_VARS */
-- 1.7.1

Re: [Dle-develop] [Qemu-devel] [PATCH v2] Add option to mlock qemu and guest memory

[Marcelo T. <mto...@re...>]

On Thu, Feb 14, 2013 at 08:21:51PM +0000, Satoru Moriya wrote:
> We have some plans to migrate legacy enterprise systems which require
> low latency (10 msec order) to kvm virtualized environment. In our
> usecase, the system runs with other untrusted guests and so locking
> memory which is used by the system is needed to avoid latency
> impacts from other guests' memory activity.
> 
> ChangeLog:
> v2
>  - Change the option name from -mlock to -realtime mlock=on|off
>  - Rebase qemu version 1.3.91
>  - Update patch description
> 
> ---
> In certain scenario, latency induced by paging is significant and
> memory locking is needed. Also, in the scenario with untrusted
> guests, latency improvement due to mlock is desired.
> 
> This patch introduces a following new option to mlock guest and
> qemu memory:
> 
> -realtime mlock=on|off
> 
> Signed-off-by: Satoru Moriya <sat...@hd...>
> ---
>  include/sysemu/os-posix.h |  1 +
>  include/sysemu/os-win32.h |  1 +
>  os-posix.c                |  8 ++++++++
>  qemu-options.hx           | 13 +++++++++++++
>  vl.c                      | 31 +++++++++++++++++++++++++++++++
>  5 files changed, 54 insertions(+)
> 
> diff --git a/include/sysemu/os-posix.h b/include/sysemu/os-posix.h
> index 7f198e4..2f2ead6 100644
> --- a/include/sysemu/os-posix.h
> +++ b/include/sysemu/os-posix.h
> @@ -31,6 +31,7 @@ void os_set_proc_name(const char *s);
>  void os_setup_signal_handling(void);
>  void os_daemonize(void);
>  void os_setup_post(void);
> +void os_mlock(void);
>  
>  typedef struct timeval qemu_timeval;
>  #define qemu_gettimeofday(tp) gettimeofday(tp, NULL)
> diff --git a/include/sysemu/os-win32.h b/include/sysemu/os-win32.h
> index bf9edeb..a74ca13 100644
> --- a/include/sysemu/os-win32.h
> +++ b/include/sysemu/os-win32.h
> @@ -80,6 +80,7 @@ static inline void os_daemonize(void) {}
>  static inline void os_setup_post(void) {}
>  void os_set_line_buffering(void);
>  static inline void os_set_proc_name(const char *dummy) {}
> +static inline void os_mlock(void) {}
>  
>  #if !defined(EPROTONOSUPPORT)
>  # define EPROTONOSUPPORT EINVAL
> diff --git a/os-posix.c b/os-posix.c
> index 5c64518..1304b0e 100644
> --- a/os-posix.c
> +++ b/os-posix.c
> @@ -363,3 +363,11 @@ bool is_daemonized(void)
>  {
>      return daemonize;
>  }
> +
> +void os_mlock(void)
> +{
> +    if (mlockall(MCL_CURRENT | MCL_FUTURE)) {
> +        perror("mlockall");
> +        exit(1);
> +    }
> +}
> diff --git a/qemu-options.hx b/qemu-options.hx
> index 9d7131a..843fcb4 100644
> --- a/qemu-options.hx
> +++ b/qemu-options.hx
> @@ -2464,6 +2464,19 @@ STEXI
>  Do not start CPU at startup (you must type 'c' in the monitor).
>  ETEXI
>  
> +DEF("realtime", HAS_ARG, QEMU_OPTION_realtime,
> +    "-realtime [mlock=on|off]\n"
> +    "                run qemu with realtime features\n"
> +    "                mlock=on|off controls mlock support (default: on)\n",
> +    QEMU_ARCH_ALL)
> +STEXI
> +@item -realtime mlock=on|off
> +@findex -realtime
> +Run qemu with realtime features.
> +mlocking qemu and guest memory can be enabled via @option{mlock=on}
> +(enabled by default).
> +ETEXI
> +
>  DEF("gdb", HAS_ARG, QEMU_OPTION_gdb, \
>      "-gdb dev        wait for gdb connection on 'dev'\n", QEMU_ARCH_ALL)
>  STEXI
> diff --git a/vl.c b/vl.c
> index 1355f69..c16c8ad 100644
> --- a/vl.c
> +++ b/vl.c
> @@ -491,6 +491,18 @@ static QemuOptsList qemu_object_opts = {
>      },
>  };
>  
> +static QemuOptsList qemu_realtime_opts = {
> +    .name = "realtime",
> +    .head = QTAILQ_HEAD_INITIALIZER(qemu_realtime_opts.head),
> +    .desc = {
> +        {
> +            .name = "mlock",
> +            .type = QEMU_OPT_BOOL,
> +        },
> +        { /* end of list */ }
> +    },
> +};
> +
>  const char *qemu_get_vm_name(void)
>  {
>      return qemu_name;
> @@ -1384,6 +1396,17 @@ static void smp_parse(const char *optarg)
>          max_cpus = smp_cpus;
>  }
>  
> +static void configure_realtime(QemuOpts *opts)
> +{
> +    bool is_mlock;
> +
> +    is_mlock = qemu_opt_get_bool(opts, "mlock", true);
> +
> +    if (is_mlock) {
> +        os_mlock();
> +    }
> +}
> +
>  /***********************************************************/
>  /* USB devices */
>  
> @@ -2860,6 +2883,7 @@ int main(int argc, char **argv, char **envp)
>      qemu_add_opts(&qemu_sandbox_opts);
>      qemu_add_opts(&qemu_add_fd_opts);
>      qemu_add_opts(&qemu_object_opts);
> +    qemu_add_opts(&qemu_realtime_opts);
>  
>      runstate_init();
>  
> @@ -3806,6 +3830,13 @@ int main(int argc, char **argv, char **envp)
>                      exit(1);
>                  }
>                  break;
> +            case QEMU_OPTION_realtime:
> +                opts = qemu_opts_parse(qemu_find_opts("realtime"), optarg, 0);
> +                if (!opts) {
> +                    exit(1);
> +                }
> +                configure_realtime(opts);
> +                break;
>              default:
>                  os_parse_cmd_args(popt->index, optarg);
>              }
> -- 
> 1.7.11.7
> 

Reviewed-by: Marcelo Tosatti <mto...@re...>

Re: [Dle-develop] [PATCH v11 1/3] tracing: Add DEFINE_EVENT_FN() macro

[Steven R. <ro...@go...>]

You still need to add:

From: Steven Rostedt <ro...@go...>

Otherwise you get the authorship of this patch.

-- Steve


On Fri, 2013-03-15 at 20:35 +0000, Seiji Aguchi wrote:
> Each TRACE_EVENT() adds several helper functions. If two or more trace events
> share the same structure and print format, they can also share most of these
> helper functions and save a lot of space from duplicate code. This is why the
> DECLARE_EVENT_CLASS() and DEFINE_EVENT() were created.
> 
> Some events require a trigger to be called at registering and unregistering of
> the event and to do so they use TRACE_EVENT_FN().
> 
> If multiple events require a trigger, they currently have no choice but to use
> TRACE_EVENT_FN() as there's no DEFINE_EVENT_FN() available. This unfortunately
> causes a lot of wasted duplicate code created.
> 
> By adding a DEFINE_EVENT_FN(), these events can still use a
> DECLARE_EVENT_CLASS() and then define their own triggers.
> 
> Signed-off-by: Steven Rostedt <ro...@go...>
> Signed-off-by: Seiji Aguchi <sei...@hd...>
> ---
>  include/linux/tracepoint.h   |    2 ++
>  include/trace/define_trace.h |    5 +++++
>  include/trace/ftrace.h       |    4 ++++
>  3 files changed, 11 insertions(+), 0 deletions(-)
> 
> diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h
> index 2f322c3..9bf59e5 100644
> --- a/include/linux/tracepoint.h
> +++ b/include/linux/tracepoint.h
> @@ -378,6 +378,8 @@ static inline void tracepoint_synchronize_unregister(void)
>  #define DECLARE_EVENT_CLASS(name, proto, args, tstruct, assign, print)
>  #define DEFINE_EVENT(template, name, proto, args)		\
>  	DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
> +#define DEFINE_EVENT_FN(template, name, proto, args, reg, unreg)\
> +	DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
>  #define DEFINE_EVENT_PRINT(template, name, proto, args, print)	\
>  	DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
>  #define DEFINE_EVENT_CONDITION(template, name, proto,		\
> diff --git a/include/trace/define_trace.h b/include/trace/define_trace.h
> index 1905ca8..02e1003 100644
> --- a/include/trace/define_trace.h
> +++ b/include/trace/define_trace.h
> @@ -44,6 +44,10 @@
>  #define DEFINE_EVENT(template, name, proto, args) \
>  	DEFINE_TRACE(name)
>  
> +#undef DEFINE_EVENT_FN
> +#define DEFINE_EVENT_FN(template, name, proto, args, reg, unreg) \
> +	DEFINE_TRACE_FN(name, reg, unreg)
> +
>  #undef DEFINE_EVENT_PRINT
>  #define DEFINE_EVENT_PRINT(template, name, proto, args, print)	\
>  	DEFINE_TRACE(name)
> @@ -91,6 +95,7 @@
>  #undef TRACE_EVENT_CONDITION
>  #undef DECLARE_EVENT_CLASS
>  #undef DEFINE_EVENT
> +#undef DEFINE_EVENT_FN
>  #undef DEFINE_EVENT_PRINT
>  #undef DEFINE_EVENT_CONDITION
>  #undef TRACE_HEADER_MULTI_READ
> diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h
> index 40dc5e8..7bab676 100644
> --- a/include/trace/ftrace.h
> +++ b/include/trace/ftrace.h
> @@ -71,6 +71,10 @@
>  	static struct ftrace_event_call	__used		\
>  	__attribute__((__aligned__(4))) event_##name
>  
> +#undef DEFINE_EVENT_FN
> +#define DEFINE_EVENT_FN(template, name, proto, args, reg, unreg)	\
> +	DEFINE_EVENT(template, name, PARAMS(proto), PARAMS(args))
> +
>  #undef DEFINE_EVENT_PRINT
>  #define DEFINE_EVENT_PRINT(template, name, proto, args, print)	\
>  	DEFINE_EVENT(template, name, PARAMS(proto), PARAMS(args))
> -- 1.7.1
> 

[Dle-develop] [Resend][PATCH v11 1/3] tracing: Add DEFINE_EVENT_FN() macro

[Seiji A. <sei...@hd...>]

From: Steven Rostedt <ro...@go...>

Each TRACE_EVENT() adds several helper functions. If two or more trace events
share the same structure and print format, they can also share most of these
helper functions and save a lot of space from duplicate code. This is why the
DECLARE_EVENT_CLASS() and DEFINE_EVENT() were created.

Some events require a trigger to be called at registering and unregistering of
the event and to do so they use TRACE_EVENT_FN().

If multiple events require a trigger, they currently have no choice but to use
TRACE_EVENT_FN() as there's no DEFINE_EVENT_FN() available. This unfortunately
causes a lot of wasted duplicate code created.

By adding a DEFINE_EVENT_FN(), these events can still use a
DECLARE_EVENT_CLASS() and then define their own triggers.

Signed-off-by: Steven Rostedt <ro...@go...>
Signed-off-by: Seiji Aguchi <sei...@hd...>
---
 include/linux/tracepoint.h   |    2 ++
 include/trace/define_trace.h |    5 +++++
 include/trace/ftrace.h       |    4 ++++
 3 files changed, 11 insertions(+), 0 deletions(-)

diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h
index 2f322c3..9bf59e5 100644
--- a/include/linux/tracepoint.h
+++ b/include/linux/tracepoint.h
@@ -378,6 +378,8 @@ static inline void tracepoint_synchronize_unregister(void)
 #define DECLARE_EVENT_CLASS(name, proto, args, tstruct, assign, print)
 #define DEFINE_EVENT(template, name, proto, args)		\
 	DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
+#define DEFINE_EVENT_FN(template, name, proto, args, reg, unreg)\
+	DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
 #define DEFINE_EVENT_PRINT(template, name, proto, args, print)	\
 	DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
 #define DEFINE_EVENT_CONDITION(template, name, proto,		\
diff --git a/include/trace/define_trace.h b/include/trace/define_trace.h
index 1905ca8..02e1003 100644
--- a/include/trace/define_trace.h
+++ b/include/trace/define_trace.h
@@ -44,6 +44,10 @@
 #define DEFINE_EVENT(template, name, proto, args) \
 	DEFINE_TRACE(name)
 
+#undef DEFINE_EVENT_FN
+#define DEFINE_EVENT_FN(template, name, proto, args, reg, unreg) \
+	DEFINE_TRACE_FN(name, reg, unreg)
+
 #undef DEFINE_EVENT_PRINT
 #define DEFINE_EVENT_PRINT(template, name, proto, args, print)	\
 	DEFINE_TRACE(name)
@@ -91,6 +95,7 @@
 #undef TRACE_EVENT_CONDITION
 #undef DECLARE_EVENT_CLASS
 #undef DEFINE_EVENT
+#undef DEFINE_EVENT_FN
 #undef DEFINE_EVENT_PRINT
 #undef DEFINE_EVENT_CONDITION
 #undef TRACE_HEADER_MULTI_READ
diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h
index 40dc5e8..7bab676 100644
--- a/include/trace/ftrace.h
+++ b/include/trace/ftrace.h
@@ -71,6 +71,10 @@
 	static struct ftrace_event_call	__used		\
 	__attribute__((__aligned__(4))) event_##name
 
+#undef DEFINE_EVENT_FN
+#define DEFINE_EVENT_FN(template, name, proto, args, reg, unreg)	\
+	DEFINE_EVENT(template, name, PARAMS(proto), PARAMS(args))
+
 #undef DEFINE_EVENT_PRINT
 #define DEFINE_EVENT_PRINT(template, name, proto, args, print)	\
 	DEFINE_EVENT(template, name, PARAMS(proto), PARAMS(args))
-- 1.7.1

Re: [Dle-develop] [PATCH v11 1/3] tracing: Add DEFINE_EVENT_FN() macro

[Seiji A. <sei...@hd...>]

> You still need to add:
> 
> From: Steven Rostedt <ro...@go...>
> 
> Otherwise you get the authorship of this patch.

My apologies.  I resend my patch 1/3 by adding it shortly.

Seiji

> -----Original Message-----
> From: Steven Rostedt [mailto:ro...@go...]
> Sent: Friday, March 15, 2013 5:10 PM
> To: Seiji Aguchi
> Cc: H. Peter Anvin (hp...@zy...); x8...@ke...; lin...@vg...; Thomas Gleixner (tg...@li...);
> 'mi...@el...' (mi...@el...); Borislav Petkov (bp...@al...); Satoru Moriya (sm...@re...); dle-
> de...@li...; lin...@vg...; Luck, Tony (ton...@in...); Paul E. McKenney
> (pa...@us...)
> Subject: Re: [PATCH v11 1/3] tracing: Add DEFINE_EVENT_FN() macro
> 
> You still need to add:
> 
> From: Steven Rostedt <ro...@go...>
> 
> Otherwise you get the authorship of this patch.
> 
> -- Steve
> 
> 
> On Fri, 2013-03-15 at 20:35 +0000, Seiji Aguchi wrote:
> > Each TRACE_EVENT() adds several helper functions. If two or more trace
> > events share the same structure and print format, they can also share
> > most of these helper functions and save a lot of space from duplicate
> > code. This is why the
> > DECLARE_EVENT_CLASS() and DEFINE_EVENT() were created.
> >
> > Some events require a trigger to be called at registering and
> > unregistering of the event and to do so they use TRACE_EVENT_FN().
> >
> > If multiple events require a trigger, they currently have no choice
> > but to use
> > TRACE_EVENT_FN() as there's no DEFINE_EVENT_FN() available. This
> > unfortunately causes a lot of wasted duplicate code created.
> >
> > By adding a DEFINE_EVENT_FN(), these events can still use a
> > DECLARE_EVENT_CLASS() and then define their own triggers.
> >
> > Signed-off-by: Steven Rostedt <ro...@go...>
> > Signed-off-by: Seiji Aguchi <sei...@hd...>
> > ---
> >  include/linux/tracepoint.h   |    2 ++
> >  include/trace/define_trace.h |    5 +++++
> >  include/trace/ftrace.h       |    4 ++++
> >  3 files changed, 11 insertions(+), 0 deletions(-)
> >
> > diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h
> > index 2f322c3..9bf59e5 100644
> > --- a/include/linux/tracepoint.h
> > +++ b/include/linux/tracepoint.h
> > @@ -378,6 +378,8 @@ static inline void
> > tracepoint_synchronize_unregister(void)
> >  #define DECLARE_EVENT_CLASS(name, proto, args, tstruct, assign, print)
> >  #define DEFINE_EVENT(template, name, proto, args)		\
> >  	DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
> > +#define DEFINE_EVENT_FN(template, name, proto, args, reg, unreg)\
> > +	DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
> >  #define DEFINE_EVENT_PRINT(template, name, proto, args, print)	\
> >  	DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
> >  #define DEFINE_EVENT_CONDITION(template, name, proto,		\
> > diff --git a/include/trace/define_trace.h
> > b/include/trace/define_trace.h index 1905ca8..02e1003 100644
> > --- a/include/trace/define_trace.h
> > +++ b/include/trace/define_trace.h
> > @@ -44,6 +44,10 @@
> >  #define DEFINE_EVENT(template, name, proto, args) \
> >  	DEFINE_TRACE(name)
> >
> > +#undef DEFINE_EVENT_FN
> > +#define DEFINE_EVENT_FN(template, name, proto, args, reg, unreg) \
> > +	DEFINE_TRACE_FN(name, reg, unreg)
> > +
> >  #undef DEFINE_EVENT_PRINT
> >  #define DEFINE_EVENT_PRINT(template, name, proto, args, print)	\
> >  	DEFINE_TRACE(name)
> > @@ -91,6 +95,7 @@
> >  #undef TRACE_EVENT_CONDITION
> >  #undef DECLARE_EVENT_CLASS
> >  #undef DEFINE_EVENT
> > +#undef DEFINE_EVENT_FN
> >  #undef DEFINE_EVENT_PRINT
> >  #undef DEFINE_EVENT_CONDITION
> >  #undef TRACE_HEADER_MULTI_READ
> > diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h index
> > 40dc5e8..7bab676 100644
> > --- a/include/trace/ftrace.h
> > +++ b/include/trace/ftrace.h
> > @@ -71,6 +71,10 @@
> >  	static struct ftrace_event_call	__used		\
> >  	__attribute__((__aligned__(4))) event_##name
> >
> > +#undef DEFINE_EVENT_FN
> > +#define DEFINE_EVENT_FN(template, name, proto, args, reg, unreg)	\
> > +	DEFINE_EVENT(template, name, PARAMS(proto), PARAMS(args))
> > +
> >  #undef DEFINE_EVENT_PRINT
> >  #define DEFINE_EVENT_PRINT(template, name, proto, args, print)	\
> >  	DEFINE_EVENT(template, name, PARAMS(proto), PARAMS(args))
> > -- 1.7.1
> >
> 

[Dle-develop] [PATCH v11 3/3] trace, x86: code-sharing between non-trace and trace irq handlers

[Seiji A. <sei...@hd...>]

[Issue]

Currently, irq vector handlers for tracing are just
copied non-trace handlers by simply inserting tracepoints.

It is difficult to manage the codes.

[Solution]

This patch shares common codes between non-trace and trace handlers
as follows to make them manageable and readable.

Non-trace irq handler:
smp_irq_handler()
{
	entering_irq(); /* pre-processing of this handler */
	__smp_irq_handler(); /*
                          * common logic between non-trace and trace handlers
                          * in a vector.
                          */
	exiting_irq(); /* post-processing of this handler */

}

Trace irq_handler:
smp_trace_irq_handler()
{
	entering_irq(); /* pre-processing of this handler */
	trace_irq_entry(); /* tracepoint for irq entry */
	__smp_irq_handler(); /*
                          * common logic between non-trace and trace handlers
                          * in a vector.
                          */
	trace_irq_exit(); /* tracepoint for irq exit */
	exiting_irq(); /* post-processing of this handler */

}

If tracepoints can place outside entering_irq()/exiting_irq() as follows, it looks \
cleaner.

smp_trace_irq_handler()
{
	trace_irq_entry();
	smp_irq_handler();
	trace_irq_exit();
}

But it doesn't work.
The problem is with irq_enter/exit() being called. They must be called before \
trace_irq_enter/exit(),  because of the rcu_irq_enter() must be called before any \
tracepoints are used, as tracepoints use  rcu to synchronize.

As a possible alternative, we may be able to call irq_enter() first as follows if \
irq_enter() can nest.

smp_trace_irq_hander()
{
	irq_entry();
	trace_irq_entry();
	smp_irq_handler();
	trace_irq_exit();
	irq_exit();
}

But it doesn't work, either.
If irq_enter() is nested, it may have a time penalty because it has to check if it \
was already called or not. The time penalty is not desired in performance sensitive \
paths even if it is tiny.
Signed-off-by: Seiji Aguchi <sei...@hd...>
---
 arch/x86/include/asm/apic.h              |   27 ++++++++
 arch/x86/kernel/apic/apic.c              |  103 ++++++++----------------------
 arch/x86/kernel/cpu/mcheck/therm_throt.c |   24 +++----
 arch/x86/kernel/cpu/mcheck/threshold.c   |   24 +++----
 arch/x86/kernel/irq.c                    |   34 +++-------
 arch/x86/kernel/irq_work.c               |   22 ++++--
 arch/x86/kernel/smp.c                    |   54 ++++++++++------
 7 files changed, 137 insertions(+), 151 deletions(-)

diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h
index 3388034..f8119b5 100644
--- a/arch/x86/include/asm/apic.h
+++ b/arch/x86/include/asm/apic.h
@@ -12,6 +12,7 @@
 #include <asm/fixmap.h>
 #include <asm/mpspec.h>
 #include <asm/msr.h>
+#include <asm/idle.h>
 
 #define ARCH_APICTIMER_STOPS_ON_C3	1
 
@@ -687,5 +688,31 @@ extern int default_check_phys_apicid_present(int phys_apicid);
 #endif
 
 #endif /* CONFIG_X86_LOCAL_APIC */
+extern void irq_enter(void);
+extern void irq_exit(void);
+
+static inline void entering_irq(void)
+{
+	irq_enter();
+	exit_idle();
+}
+
+static inline void entering_ack_irq(void)
+{
+	ack_APIC_irq();
+	entering_irq();
+}
+
+static inline void exiting_irq(void)
+{
+	irq_exit();
+}
+
+static inline void exiting_ack_irq(void)
+{
+	irq_exit();
+	/* Ack only at the end to avoid potential reentry */
+	ack_APIC_irq();
+}
 
 #endif /* _ASM_X86_APIC_H */
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index 7d39c68..61ced40 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -922,17 +922,14 @@ void __irq_entry smp_apic_timer_interrupt(struct pt_regs *regs)
 	/*
 	 * NOTE! We'd better ACK the irq immediately,
 	 * because timer handling can be slow.
-	 */
-	ack_APIC_irq();
-	/*
+	 *
 	 * update_process_times() expects us to have done irq_enter().
 	 * Besides, if we don't timer interrupts ignore the global
 	 * interrupt lock, which is the WrongThing (tm) to do.
 	 */
-	irq_enter();
-	exit_idle();
+	entering_ack_irq();
 	local_apic_timer_interrupt();
-	irq_exit();
+	exiting_irq();
 
 	set_irq_regs(old_regs);
 }
@@ -944,19 +941,16 @@ void __irq_entry smp_trace_apic_timer_interrupt(struct pt_regs *regs)
 	/*
 	 * NOTE! We'd better ACK the irq immediately,
 	 * because timer handling can be slow.
-	 */
-	ack_APIC_irq();
-	/*
+	 *
 	 * update_process_times() expects us to have done irq_enter().
 	 * Besides, if we don't timer interrupts ignore the global
 	 * interrupt lock, which is the WrongThing (tm) to do.
 	 */
-	irq_enter();
-	exit_idle();
+	entering_ack_irq();
 	trace_local_timer_entry(LOCAL_TIMER_VECTOR);
 	local_apic_timer_interrupt();
 	trace_local_timer_exit(LOCAL_TIMER_VECTOR);
-	irq_exit();
+	exiting_irq();
 
 	set_irq_regs(old_regs);
 }
@@ -1934,12 +1928,10 @@ int __init APIC_init_uniprocessor(void)
 /*
  * This interrupt should _never_ happen with our APIC/SMP architecture
  */
-void smp_spurious_interrupt(struct pt_regs *regs)
+static inline void __smp_spurious_interrupt(void)
 {
 	u32 v;
 
-	irq_enter();
-	exit_idle();
 	/*
 	 * Check if this really is a spurious interrupt and ACK it
 	 * if it is a vectored one.  Just in case...
@@ -1954,38 +1946,28 @@ void smp_spurious_interrupt(struct pt_regs *regs)
 	/* see sw-dev-man vol 3, chapter 7.4.13.5 */
 	pr_info("spurious APIC interrupt on CPU#%d, "
 		"should never happen.\n", smp_processor_id());
-	irq_exit();
 }
 
-void smp_trace_spurious_interrupt(struct pt_regs *regs)
+void smp_spurious_interrupt(struct pt_regs *regs)
 {
-	u32 v;
+	entering_irq();
+	__smp_spurious_interrupt();
+	exiting_irq();
+}
 
-	irq_enter();
-	exit_idle();
+void smp_trace_spurious_interrupt(struct pt_regs *regs)
+{
+	entering_irq();
 	trace_spurious_apic_entry(SPURIOUS_APIC_VECTOR);
-	/*
-	 * Check if this really is a spurious interrupt and ACK it
-	 * if it is a vectored one.  Just in case...
-	 * Spurious interrupts should not be ACKed.
-	 */
-	v = apic_read(APIC_ISR + ((SPURIOUS_APIC_VECTOR & ~0x1f) >> 1));
-	if (v & (1 << (SPURIOUS_APIC_VECTOR & 0x1f)))
-		ack_APIC_irq();
-
-	inc_irq_stat(irq_spurious_count);
-
-	/* see sw-dev-man vol 3, chapter 7.4.13.5 */
-	pr_info("spurious APIC interrupt on CPU#%d, "
-		"should never happen.\n", smp_processor_id());
+	__smp_spurious_interrupt();
 	trace_spurious_apic_exit(SPURIOUS_APIC_VECTOR);
-	irq_exit();
+	exiting_irq();
 }
 
 /*
  * This interrupt should never happen with our APIC/SMP architecture
  */
-void smp_error_interrupt(struct pt_regs *regs)
+static inline void __smp_error_interrupt(struct pt_regs *regs)
 {
 	u32 v0, v1;
 	u32 i = 0;
@@ -2000,8 +1982,6 @@ void smp_error_interrupt(struct pt_regs *regs)
 		"Illegal register address",	/* APIC Error Bit 7 */
 	};
 
-	irq_enter();
-	exit_idle();
 	/* First tickle the hardware, only then report what went on. -- REW */
 	v0 = apic_read(APIC_ESR);
 	apic_write(APIC_ESR, 0);
@@ -2022,49 +2002,22 @@ void smp_error_interrupt(struct pt_regs *regs)
 
 	apic_printk(APIC_DEBUG, KERN_CONT "\n");
 
-	irq_exit();
 }
 
-void smp_trace_error_interrupt(struct pt_regs *regs)
+void smp_error_interrupt(struct pt_regs *regs)
 {
-	u32 v0, v1;
-	u32 i = 0;
-	static const char * const error_interrupt_reason[] = {
-		"Send CS error",		/* APIC Error Bit 0 */
-		"Receive CS error",		/* APIC Error Bit 1 */
-		"Send accept error",		/* APIC Error Bit 2 */
-		"Receive accept error",		/* APIC Error Bit 3 */
-		"Redirectable IPI",		/* APIC Error Bit 4 */
-		"Send illegal vector",		/* APIC Error Bit 5 */
-		"Received illegal vector",	/* APIC Error Bit 6 */
-		"Illegal register address",	/* APIC Error Bit 7 */
-	};
+	entering_irq();
+	__smp_error_interrupt(regs);
+	exiting_irq();
+}
 
-	irq_enter();
-	exit_idle();
+void smp_trace_error_interrupt(struct pt_regs *regs)
+{
+	entering_irq();
 	trace_error_apic_entry(ERROR_APIC_VECTOR);
-	/* First tickle the hardware, only then report what went on. -- REW */
-	v0 = apic_read(APIC_ESR);
-	apic_write(APIC_ESR, 0);
-	v1 = apic_read(APIC_ESR);
-	ack_APIC_irq();
-	atomic_inc(&irq_err_count);
-
-	apic_printk(APIC_DEBUG, KERN_DEBUG "APIC error on CPU%d: %02x(%02x)",
-		    smp_processor_id(), v0 , v1);
-
-	v1 = v1 & 0xff;
-	while (v1) {
-		if (v1 & 0x1)
-			apic_printk(APIC_DEBUG, KERN_CONT " : %s", error_interrupt_reason[i]);
-		i++;
-		v1 >>= 1;
-	}
-
-	apic_printk(APIC_DEBUG, KERN_CONT "\n");
-
+	__smp_error_interrupt(regs);
 	trace_error_apic_exit(ERROR_APIC_VECTOR);
-	irq_exit();
+	exiting_irq();
 }
 
 /**
diff --git a/arch/x86/kernel/cpu/mcheck/therm_throt.c b/arch/x86/kernel/cpu/mcheck/therm_throt.c
index e7aa7fc..2f3a799 100644
--- a/arch/x86/kernel/cpu/mcheck/therm_throt.c
+++ b/arch/x86/kernel/cpu/mcheck/therm_throt.c
@@ -379,28 +379,26 @@ static void unexpected_thermal_interrupt(void)
 
 static void (*smp_thermal_vector)(void) = unexpected_thermal_interrupt;
 
-asmlinkage void smp_thermal_interrupt(struct pt_regs *regs)
+static inline void __smp_thermal_interrupt(void)
 {
-	irq_enter();
-	exit_idle();
 	inc_irq_stat(irq_thermal_count);
 	smp_thermal_vector();
-	irq_exit();
-	/* Ack only at the end to avoid potential reentry */
-	ack_APIC_irq();
+}
+
+asmlinkage void smp_thermal_interrupt(struct pt_regs *regs)
+{
+	entering_irq();
+	__smp_thermal_interrupt();
+	exiting_ack_irq();
 }
 
 asmlinkage void smp_trace_thermal_interrupt(struct pt_regs *regs)
 {
-	irq_enter();
-	exit_idle();
+	entering_irq();
 	trace_thermal_apic_entry(THERMAL_APIC_VECTOR);
-	inc_irq_stat(irq_thermal_count);
-	smp_thermal_vector();
+	__smp_thermal_interrupt();
 	trace_thermal_apic_exit(THERMAL_APIC_VECTOR);
-	irq_exit();
-	/* Ack only at the end to avoid potential reentry */
-	ack_APIC_irq();
+	exiting_ack_irq();
 }
 
 /* Thermal monitoring depends on APIC, ACPI and clock modulation */
diff --git a/arch/x86/kernel/cpu/mcheck/threshold.c b/arch/x86/kernel/cpu/mcheck/threshold.c
index 0cbef99..fe6b1c8 100644
--- a/arch/x86/kernel/cpu/mcheck/threshold.c
+++ b/arch/x86/kernel/cpu/mcheck/threshold.c
@@ -18,26 +18,24 @@ static void default_threshold_interrupt(void)
 
 void (*mce_threshold_vector)(void) = default_threshold_interrupt;
 
-asmlinkage void smp_threshold_interrupt(void)
+static inline void __smp_threshold_interrupt(void)
 {
-	irq_enter();
-	exit_idle();
 	inc_irq_stat(irq_threshold_count);
 	mce_threshold_vector();
-	irq_exit();
-	/* Ack only at the end to avoid potential reentry */
-	ack_APIC_irq();
+}
+
+asmlinkage void smp_threshold_interrupt(void)
+{
+	entering_irq();
+	__smp_threshold_interrupt();
+	exiting_ack_irq();
 }
 
 asmlinkage void smp_trace_threshold_interrupt(void)
 {
-	irq_enter();
-	exit_idle();
+	entering_irq();
 	trace_threshold_apic_entry(THRESHOLD_APIC_VECTOR);
-	inc_irq_stat(irq_threshold_count);
-	mce_threshold_vector();
+	__smp_threshold_interrupt();
 	trace_threshold_apic_exit(THRESHOLD_APIC_VECTOR);
-	irq_exit();
-	/* Ack only at the end to avoid potential reentry */
-	ack_APIC_irq();
+	exiting_ack_irq();
 }
diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c
index 216bec1..ae836cd 100644
--- a/arch/x86/kernel/irq.c
+++ b/arch/x86/kernel/irq.c
@@ -209,23 +209,21 @@ unsigned int __irq_entry do_IRQ(struct pt_regs *regs)
 /*
  * Handler for X86_PLATFORM_IPI_VECTOR.
  */
-void smp_x86_platform_ipi(struct pt_regs *regs)
+void __smp_x86_platform_ipi(void)
 {
-	struct pt_regs *old_regs = set_irq_regs(regs);
-
-	ack_APIC_irq();
-
-	irq_enter();
-
-	exit_idle();
-
 	inc_irq_stat(x86_platform_ipis);
 
 	if (x86_platform_ipi_callback)
 		x86_platform_ipi_callback();
+}
 
-	irq_exit();
+void smp_x86_platform_ipi(struct pt_regs *regs)
+{
+	struct pt_regs *old_regs = set_irq_regs(regs);
 
+	entering_ack_irq();
+	__smp_x86_platform_ipi();
+	exiting_irq();
 	set_irq_regs(old_regs);
 }
 
@@ -233,21 +231,11 @@ void smp_trace_x86_platform_ipi(struct pt_regs *regs)
 {
 	struct pt_regs *old_regs = set_irq_regs(regs);
 
-	ack_APIC_irq();
-
-	irq_enter();
-
-	exit_idle();
-
+	entering_ack_irq();
 	trace_x86_platform_ipi_entry(X86_PLATFORM_IPI_VECTOR);
-	inc_irq_stat(x86_platform_ipis);
-
-	if (x86_platform_ipi_callback)
-		x86_platform_ipi_callback();
-
+	__smp_x86_platform_ipi();
 	trace_x86_platform_ipi_exit(X86_PLATFORM_IPI_VECTOR);
-	irq_exit();
-
+	exiting_irq();
 	set_irq_regs(old_regs);
 }
 
diff --git a/arch/x86/kernel/irq_work.c b/arch/x86/kernel/irq_work.c
index 09e6262..636a55e 100644
--- a/arch/x86/kernel/irq_work.c
+++ b/arch/x86/kernel/irq_work.c
@@ -10,24 +10,32 @@
 #include <asm/apic.h>
 #include <asm/trace/irq_vectors.h>
 
-void smp_irq_work_interrupt(struct pt_regs *regs)
+static inline void irq_work_entering_irq(void)
 {
 	irq_enter();
 	ack_APIC_irq();
+}
+
+static inline void __smp_irq_work_interrupt(void)
+{
 	inc_irq_stat(apic_irq_work_irqs);
 	irq_work_run();
-	irq_exit();
+}
+
+void smp_irq_work_interrupt(struct pt_regs *regs)
+{
+	irq_work_entering_irq();
+	__smp_irq_work_interrupt();
+	exiting_irq();
 }
 
 void smp_trace_irq_work_interrupt(struct pt_regs *regs)
 {
-	irq_enter();
-	ack_APIC_irq();
+	irq_work_entering_irq();
 	trace_irq_work_entry(IRQ_WORK_VECTOR);
-	inc_irq_stat(apic_irq_work_irqs);
-	irq_work_run();
+	__smp_irq_work_interrupt();
 	trace_irq_work_exit(IRQ_WORK_VECTOR);
-	irq_exit();
+	exiting_irq();
 }
 
 void arch_irq_work_raise(void)
diff --git a/arch/x86/kernel/smp.c b/arch/x86/kernel/smp.c
index aad58af..f4fe0b8 100644
--- a/arch/x86/kernel/smp.c
+++ b/arch/x86/kernel/smp.c
@@ -250,11 +250,16 @@ finish:
 /*
  * Reschedule call back.
  */
-void smp_reschedule_interrupt(struct pt_regs *regs)
+static inline void __smp_reschedule_interrupt(void)
 {
-	ack_APIC_irq();
 	inc_irq_stat(irq_resched_count);
 	scheduler_ipi();
+}
+
+void smp_reschedule_interrupt(struct pt_regs *regs)
+{
+	ack_APIC_irq();
+	__smp_reschedule_interrupt();
 	/*
 	 * KVM uses this interrupt to force a cpu out of guest mode
 	 */
@@ -264,52 +269,61 @@ void smp_trace_reschedule_interrupt(struct pt_regs *regs)
 {
 	ack_APIC_irq();
 	trace_reschedule_entry(RESCHEDULE_VECTOR);
-	inc_irq_stat(irq_resched_count);
-	scheduler_ipi();
+	__smp_reschedule_interrupt();
 	trace_reschedule_exit(RESCHEDULE_VECTOR);
 	/*
 	 * KVM uses this interrupt to force a cpu out of guest mode
 	 */
 }
 
-void smp_call_function_interrupt(struct pt_regs *regs)
+static inline void call_function_entering_irq(void)
 {
 	ack_APIC_irq();
 	irq_enter();
+}
+
+static inline void __smp_call_function_interrupt(void)
+{
 	generic_smp_call_function_interrupt();
 	inc_irq_stat(irq_call_count);
-	irq_exit();
+}
+
+void smp_call_function_interrupt(struct pt_regs *regs)
+{
+	call_function_entering_irq();
+	__smp_call_function_interrupt();
+	exiting_irq();
 }
 
 void smp_trace_call_function_interrupt(struct pt_regs *regs)
 {
-	ack_APIC_irq();
-	irq_enter();
+	call_function_entering_irq();
 	trace_call_function_entry(CALL_FUNCTION_VECTOR);
-	generic_smp_call_function_interrupt();
-	inc_irq_stat(irq_call_count);
+	__smp_call_function_interrupt();
 	trace_call_function_exit(CALL_FUNCTION_VECTOR);
-	irq_exit();
+	exiting_irq();
 }
 
-void smp_call_function_single_interrupt(struct pt_regs *regs)
+static inline void __smp_call_function_single_interrupt(void)
 {
-	ack_APIC_irq();
-	irq_enter();
 	generic_smp_call_function_single_interrupt();
 	inc_irq_stat(irq_call_count);
-	irq_exit();
+}
+
+void smp_call_function_single_interrupt(struct pt_regs *regs)
+{
+	call_function_entering_irq();
+	__smp_call_function_single_interrupt();
+	exiting_irq();
 }
 
 void smp_trace_call_function_single_interrupt(struct pt_regs *regs)
 {
-	ack_APIC_irq();
-	irq_enter();
+	call_function_entering_irq();
 	trace_call_function_single_entry(CALL_FUNCTION_SINGLE_VECTOR);
-	generic_smp_call_function_single_interrupt();
-	inc_irq_stat(irq_call_count);
+	__smp_call_function_single_interrupt();
 	trace_call_function_single_exit(CALL_FUNCTION_SINGLE_VECTOR);
-	irq_exit();
+	exiting_irq();
 }
 
 static int __init nonmi_ipi_setup(char *str)
-- 1.7.1

[Dle-develop] [PATCH v11 2/3] trace, x86: add x86 irq vector tracepoints

[Seiji A. <sei...@hd...>]

[Purpose of this patch]

As Vaibhav explained in the thread below, tracepoints for irq vectors
are useful.

http://www.spinics.net/lists/mm-commits/msg85707.html

<snip>
The current interrupt traces from irq_handler_entry and irq_handler_exit
provide when an interrupt is handled.  They provide good data about when
the system has switched to kernel space and how it affects the currently
running processes.

There are some IRQ vectors which trigger the system into kernel space,
which are not handled in generic IRQ handlers.  Tracing such events gives
us the information about IRQ interaction with other system events.

The trace also tells where the system is spending its time.  We want to
know which cores are handling interrupts and how they are affecting other
processes in the system.  Also, the trace provides information about when
the cores are idle and which interrupts are changing that state.
<snip>

On the other hand, my usecase is tracing just local timer event and
getting a value of instruction pointer.

I suggested to add an argument local timer event to get instruction pointer before.
But there is another way to get it with external module like systemtap.
So, I don't need to add any argument to irq vector tracepoints now.

[Patch Description]

Vaibhav's patch shared a trace point ,irq_vector_entry/irq_vector_exit, in all events.
But there is an above use case to trace specific irq_vector rather than tracing all events.
In this case, we are concerned about overhead due to unwanted events.

This patch adds following tracepoints instead of introducing irq_vector_entry/exit.
so that we can enable them independently.
   - local_timer_vector
   - reschedule_vector
   - call_function_vector
   - call_function_single_vector
   - irq_work_entry_vector
   - error_apic_vector
   - thermal_apic_vector
   - threshold_apic_vector
   - spurious_apic_vector
   - x86_platform_ipi_vector

Also, it introduces a logic switching IDT at enabling/disabling time so that a time penalty
makes a zero when tracepoints are disabled. Detailed explanations are as follows.
 - Duplicate new irq handlers inserted tracepoints.
 - Create a new IDT, trace_idt_table, at boot time by adding a logic to
   _set_gate(). It is just a copy of original idt table.
 - Registering the new handers for tracpoints to the new IDT by introducing
   macros to alloc_intr_gate() called at regstering time of irq_vector handlers.
 - Switch IDT to new one at enabling TP time.
 - Restore to an original IDT at disabling TP time.
The new IDT is created only when CONFIG_TRACING is enabled to avoid being used for other purposes.

Signed-off-by: Seiji Aguchi <sei...@hd...>
---
 arch/x86/include/asm/desc.h              |   36 +++++++-
 arch/x86/include/asm/entry_arch.h        |    5 +-
 arch/x86/include/asm/hw_irq.h            |   16 +++
 arch/x86/include/asm/mshyperv.h          |    1 +
 arch/x86/include/asm/trace/irq_vectors.h |  159 ++++++++++++++++++++++++++++++
 arch/x86/kernel/Makefile                 |    1 +
 arch/x86/kernel/apic/apic.c              |   94 ++++++++++++++++++
 arch/x86/kernel/cpu/common.c             |   12 ++-
 arch/x86/kernel/cpu/mcheck/therm_throt.c |   14 +++
 arch/x86/kernel/cpu/mcheck/threshold.c   |   14 +++
 arch/x86/kernel/entry_32.S               |   12 ++-
 arch/x86/kernel/entry_64.S               |   29 +++++-
 arch/x86/kernel/head_64.S                |    6 +
 arch/x86/kernel/irq.c                    |   23 +++++
 arch/x86/kernel/irq_work.c               |   12 +++
 arch/x86/kernel/smp.c                    |   35 +++++++
 arch/x86/kernel/tracepoint.c             |   71 +++++++++++++
 include/xen/events.h                     |    3 +
 18 files changed, 529 insertions(+), 14 deletions(-)
 create mode 100644 arch/x86/include/asm/trace/irq_vectors.h
 create mode 100644 arch/x86/kernel/tracepoint.c

diff --git a/arch/x86/include/asm/desc.h b/arch/x86/include/asm/desc.h
index 8bf1c06..e718c72 100644
--- a/arch/x86/include/asm/desc.h
+++ b/arch/x86/include/asm/desc.h
@@ -39,6 +39,9 @@ extern gate_desc idt_table[];
 extern struct desc_ptr nmi_idt_descr;
 extern gate_desc nmi_idt_table[];

+extern struct desc_ptr trace_idt_descr;
+extern DEFINE_PER_CPU(u32, trace_idt_in_use);
+extern DEFINE_PER_CPU(u32, debug_stack_use_ctr);
 struct gdt_page {
 	struct desc_struct gdt[GDT_ENTRIES];
 } __attribute__((aligned(PAGE_SIZE)));
@@ -320,6 +323,17 @@ static inline void set_nmi_gate(int gate, void *addr)
 }
 #endif

+#ifdef CONFIG_TRACING
+extern gate_desc trace_idt_table[];
+static inline void trace_set_intr_gate(unsigned int gate, void *addr)
+{
+	gate_desc s;
+
+	pack_gate(&s, GATE_INTERRUPT, (unsigned long)addr, 0, 0, __KERNEL_CS);
+	write_idt_entry(trace_idt_table, gate, &s);
+}
+#endif
+
 static inline void _set_gate(int gate, unsigned type, void *addr,
 			     unsigned dpl, unsigned ist, unsigned seg)
 {
@@ -331,6 +345,9 @@ static inline void _set_gate(int gate, unsigned type, void *addr,
 	 * setup time
 	 */
 	write_idt_entry(idt_table, gate, &s);
+#ifdef CONFIG_TRACING
+	write_idt_entry(trace_idt_table, gate, &s);
+#endif
 }

 /*
@@ -360,12 +377,27 @@ static inline void alloc_system_vector(int vector)
 	}
 }

-static inline void alloc_intr_gate(unsigned int n, void *addr)
+#ifdef CONFIG_TRACING
+static inline void __trace_alloc_intr_gate(unsigned int n, void *addr)
+{
+	trace_set_intr_gate(n, addr);
+}
+#else
+#define __trace_alloc_intr_gate(n, addr)
+#endif
+
+static inline void __alloc_intr_gate(unsigned int n, void *addr)
 {
-	alloc_system_vector(n);
 	set_intr_gate(n, addr);
 }

+#define alloc_intr_gate(n, addr)				\
+	do {							\
+		alloc_system_vector(n);				\
+		__alloc_intr_gate(n, addr);			\
+		__trace_alloc_intr_gate(n, trace_##addr);	\
+	} while (0)
+
 /*
  * This routine sets up an interrupt gate at directory privilege level 3.
  */
diff --git a/arch/x86/include/asm/entry_arch.h b/arch/x86/include/asm/entry_arch.h
index 40afa00..0bb99d8 100644
--- a/arch/x86/include/asm/entry_arch.h
+++ b/arch/x86/include/asm/entry_arch.h
@@ -13,8 +13,9 @@
 BUILD_INTERRUPT(reschedule_interrupt,RESCHEDULE_VECTOR)
 BUILD_INTERRUPT(call_function_interrupt,CALL_FUNCTION_VECTOR)
 BUILD_INTERRUPT(call_function_single_interrupt,CALL_FUNCTION_SINGLE_VECTOR)
-BUILD_INTERRUPT(irq_move_cleanup_interrupt,IRQ_MOVE_CLEANUP_VECTOR)
-BUILD_INTERRUPT(reboot_interrupt,REBOOT_VECTOR)
+BUILD_INTERRUPT3(irq_move_cleanup_interrupt, IRQ_MOVE_CLEANUP_VECTOR,
+		 smp_irq_move_cleanup_interrupt)
+BUILD_INTERRUPT3(reboot_interrupt, REBOOT_VECTOR, smp_reboot_interrupt)
 #endif

 BUILD_INTERRUPT(x86_platform_ipi, X86_PLATFORM_IPI_VECTOR)
diff --git a/arch/x86/include/asm/hw_irq.h b/arch/x86/include/asm/hw_irq.h
index 10a78c3..e84e91a 100644
--- a/arch/x86/include/asm/hw_irq.h
+++ b/arch/x86/include/asm/hw_irq.h
@@ -76,6 +76,22 @@ extern void threshold_interrupt(void);
 extern void call_function_interrupt(void);
 extern void call_function_single_interrupt(void);

+#ifdef CONFIG_TRACING
+/* Interrupt handlers registered during init_IRQ */
+extern void trace_apic_timer_interrupt(void);
+extern void trace_x86_platform_ipi(void);
+extern void trace_error_interrupt(void);
+extern void trace_irq_work_interrupt(void);
+extern void trace_spurious_interrupt(void);
+extern void trace_thermal_interrupt(void);
+extern void trace_reschedule_interrupt(void);
+extern void trace_threshold_interrupt(void);
+extern void trace_call_function_interrupt(void);
+extern void trace_call_function_single_interrupt(void);
+#define trace_irq_move_cleanup_interrupt  irq_move_cleanup_interrupt
+#define trace_reboot_interrupt  reboot_interrupt
+#endif /* CONFIG_TRACING */
+
 /* IOAPIC */
 #define IO_APIC_IRQ(x) (((x) >= NR_IRQS_LEGACY) || ((1<<(x)) & io_apic_irqs))
 extern unsigned long io_apic_irqs;
diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index c2934be..cc40e03 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -12,6 +12,7 @@ struct ms_hyperv_info {
 extern struct ms_hyperv_info ms_hyperv;

 void hyperv_callback_vector(void);
+#define trace_hyperv_callback_vector hyperv_callback_vector
 void hyperv_vector_handler(struct pt_regs *regs);
 void hv_register_vmbus_handler(int irq, irq_handler_t handler);

diff --git a/arch/x86/include/asm/trace/irq_vectors.h b/arch/x86/include/asm/trace/irq_vectors.h
new file mode 100644
index 0000000..b4f1c53
--- /dev/null
+++ b/arch/x86/include/asm/trace/irq_vectors.h
@@ -0,0 +1,159 @@
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM irq_vectors
+
+#if !defined(_TRACE_IRQ_VECTORS_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_IRQ_VECTORS_H
+
+#include <linux/tracepoint.h>
+
+extern void trace_irq_vector_regfunc(void);
+extern void trace_irq_vector_unregfunc(void);
+
+DECLARE_EVENT_CLASS(x86_irq_vector,
+
+	TP_PROTO(int vector),
+
+	TP_ARGS(vector),
+
+	TP_STRUCT__entry(
+		__field(		int,	vector	)
+	),
+
+	TP_fast_assign(
+		__entry->vector = vector;
+	),
+
+	TP_printk("vector=%d", __entry->vector) );
+
+#define DEFINE_IRQ_VECTOR_EVENT(name)	\
+DEFINE_EVENT_FN(x86_irq_vector, name,	\
+	TP_PROTO(int vector),		\
+	TP_ARGS(vector),		\
+	trace_irq_vector_regfunc,	\
+	trace_irq_vector_unregfunc);
+
+/*
+ * local_timer_entry - called before entering a local timer interrupt
+ * vector handler
+ */
+DEFINE_IRQ_VECTOR_EVENT(local_timer_entry);
+
+/*
+ * local_timer_exit - called immediately after the interrupt vector
+ * handler returns
+ */
+DEFINE_IRQ_VECTOR_EVENT(local_timer_exit);
+
+/*
+ * reschedule_entry - called before entering a reschedule vector handler
+ */
+DEFINE_IRQ_VECTOR_EVENT(reschedule_entry);
+
+/*
+ * reschedule_exit - called immediately after the interrupt vector
+ * handler returns
+ */
+DEFINE_IRQ_VECTOR_EVENT(reschedule_exit);
+
+/*
+ * spurious_apic_entry - called before entering a spurious apic vector handler
+ */
+DEFINE_IRQ_VECTOR_EVENT(spurious_apic_entry);
+
+/*
+ * spurious_apic_exit - called immediately after the interrupt vector
+ * handler returns
+ */
+DEFINE_IRQ_VECTOR_EVENT(spurious_apic_exit);
+
+/*
+ * error_apic_entry - called before entering an error apic vector handler
+ */
+DEFINE_IRQ_VECTOR_EVENT(error_apic_entry);
+
+/*
+ * error_apic_exit - called immediately after the interrupt vector
+ * handler returns
+ */
+DEFINE_IRQ_VECTOR_EVENT(error_apic_exit);
+
+/*
+ * x86_platform_ipi_entry - called before entering a x86 platform ipi interrupt
+ * vector handler
+ */
+DEFINE_IRQ_VECTOR_EVENT(x86_platform_ipi_entry);
+
+/*
+ * x86_platform_ipi_exit - called immediately after the interrupt vector
+ * handler returns
+ */
+DEFINE_IRQ_VECTOR_EVENT(x86_platform_ipi_exit);
+
+/*
+ * irq_work_entry - called before entering a irq work interrupt
+ * vector handler
+ */
+DEFINE_IRQ_VECTOR_EVENT(irq_work_entry);
+
+/*
+ * irq_work_exit - called immediately after the interrupt vector
+ * handler returns
+ */
+DEFINE_IRQ_VECTOR_EVENT(irq_work_exit);
+
+/*
+ * call_function_entry - called before entering a call function interrupt
+ * vector handler
+ */
+DEFINE_IRQ_VECTOR_EVENT(call_function_entry);
+
+/*
+ * call_function_exit - called immediately after the interrupt vector
+ * handler returns
+ */
+DEFINE_IRQ_VECTOR_EVENT(call_function_exit);
+
+/*
+ * call_function_single_entry - called before entering a call function
+ * single interrupt vector handler
+ */
+DEFINE_IRQ_VECTOR_EVENT(call_function_single_entry);
+
+/*
+ * call_function_single_exit - called immediately after the interrupt vector
+ * handler returns
+ */
+DEFINE_IRQ_VECTOR_EVENT(call_function_single_exit);
+
+/*
+ * threshold_apic_entry - called before entering a threshold apic interrupt
+ * vector handler
+ */
+DEFINE_IRQ_VECTOR_EVENT(threshold_apic_entry);
+
+/*
+ * threshold_apic_exit - called immediately after the interrupt vector
+ * handler returns
+ */
+DEFINE_IRQ_VECTOR_EVENT(threshold_apic_exit);
+
+/*
+ * thermal_apic_entry - called before entering a thermal apic interrupt
+ * vector handler
+ */
+DEFINE_IRQ_VECTOR_EVENT(thermal_apic_entry);
+
+/*
+ * thrmal_apic_exit - called immediately after the interrupt vector
+ * handler returns
+ */
+DEFINE_IRQ_VECTOR_EVENT(thermal_apic_exit);
+
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH ../../arch/x86/include/asm/trace
+#define TRACE_INCLUDE_FILE irq_vectors
+#endif /*  _TRACE_IRQ_VECTORS_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>
+
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index 7bd3bd3..74b3891 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -102,6 +102,7 @@ obj-$(CONFIG_OF)			+= devicetree.o
 obj-$(CONFIG_UPROBES)			+= uprobes.o

 obj-$(CONFIG_PERF_EVENTS)		+= perf_regs.o
+obj-$(CONFIG_TRACING)			+= tracepoint.o

 ###
 # 64 bit specific files
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index 904611b..7d39c68 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -55,6 +55,9 @@
 #include <asm/tsc.h>
 #include <asm/hypervisor.h>

+#define CREATE_TRACE_POINTS
+#include <asm/trace/irq_vectors.h>
+
 unsigned int num_processors;

 unsigned disabled_cpus __cpuinitdata;
@@ -934,6 +937,30 @@ void __irq_entry smp_apic_timer_interrupt(struct pt_regs *regs)
 	set_irq_regs(old_regs);
 }

+void __irq_entry smp_trace_apic_timer_interrupt(struct pt_regs *regs)
+{
+	struct pt_regs *old_regs = set_irq_regs(regs);
+
+	/*
+	 * NOTE! We'd better ACK the irq immediately,
+	 * because timer handling can be slow.
+	 */
+	ack_APIC_irq();
+	/*
+	 * update_process_times() expects us to have done irq_enter().
+	 * Besides, if we don't timer interrupts ignore the global
+	 * interrupt lock, which is the WrongThing (tm) to do.
+	 */
+	irq_enter();
+	exit_idle();
+	trace_local_timer_entry(LOCAL_TIMER_VECTOR);
+	local_apic_timer_interrupt();
+	trace_local_timer_exit(LOCAL_TIMER_VECTOR);
+	irq_exit();
+
+	set_irq_regs(old_regs);
+}
+
 int setup_profiling_timer(unsigned int multiplier)
 {
 	return -EINVAL;
@@ -1930,6 +1957,31 @@ void smp_spurious_interrupt(struct pt_regs *regs)
 	irq_exit();
 }

+void smp_trace_spurious_interrupt(struct pt_regs *regs)
+{
+	u32 v;
+
+	irq_enter();
+	exit_idle();
+	trace_spurious_apic_entry(SPURIOUS_APIC_VECTOR);
+	/*
+	 * Check if this really is a spurious interrupt and ACK it
+	 * if it is a vectored one.  Just in case...
+	 * Spurious interrupts should not be ACKed.
+	 */
+	v = apic_read(APIC_ISR + ((SPURIOUS_APIC_VECTOR & ~0x1f) >> 1));
+	if (v & (1 << (SPURIOUS_APIC_VECTOR & 0x1f)))
+		ack_APIC_irq();
+
+	inc_irq_stat(irq_spurious_count);
+
+	/* see sw-dev-man vol 3, chapter 7.4.13.5 */
+	pr_info("spurious APIC interrupt on CPU#%d, "
+		"should never happen.\n", smp_processor_id());
+	trace_spurious_apic_exit(SPURIOUS_APIC_VECTOR);
+	irq_exit();
+}
+
 /*
  * This interrupt should never happen with our APIC/SMP architecture
  */
@@ -1973,6 +2025,48 @@ void smp_error_interrupt(struct pt_regs *regs)
 	irq_exit();
 }

+void smp_trace_error_interrupt(struct pt_regs *regs)
+{
+	u32 v0, v1;
+	u32 i = 0;
+	static const char * const error_interrupt_reason[] = {
+		"Send CS error",		/* APIC Error Bit 0 */
+		"Receive CS error",		/* APIC Error Bit 1 */
+		"Send accept error",		/* APIC Error Bit 2 */
+		"Receive accept error",		/* APIC Error Bit 3 */
+		"Redirectable IPI",		/* APIC Error Bit 4 */
+		"Send illegal vector",		/* APIC Error Bit 5 */
+		"Received illegal vector",	/* APIC Error Bit 6 */
+		"Illegal register address",	/* APIC Error Bit 7 */
+	};
+
+	irq_enter();
+	exit_idle();
+	trace_error_apic_entry(ERROR_APIC_VECTOR);
+	/* First tickle the hardware, only then report what went on. -- REW */
+	v0 = apic_read(APIC_ESR);
+	apic_write(APIC_ESR, 0);
+	v1 = apic_read(APIC_ESR);
+	ack_APIC_irq();
+	atomic_inc(&irq_err_count);
+
+	apic_printk(APIC_DEBUG, KERN_DEBUG "APIC error on CPU%d: %02x(%02x)",
+		    smp_processor_id(), v0 , v1);
+
+	v1 = v1 & 0xff;
+	while (v1) {
+		if (v1 & 0x1)
+			apic_printk(APIC_DEBUG, KERN_CONT " : %s", error_interrupt_reason[i]);
+		i++;
+		v1 >>= 1;
+	}
+
+	apic_printk(APIC_DEBUG, KERN_CONT "\n");
+
+	trace_error_apic_exit(ERROR_APIC_VECTOR);
+	irq_exit();
+}
+
 /**
  * connect_bsp_APIC - attach the APIC to the interrupt system
  */
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index d814772..23045cd 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -1144,7 +1144,7 @@ int is_debug_stack(unsigned long addr)
 		 addr > (__get_cpu_var(debug_stack_addr) - DEBUG_STKSZ));
 }

-static DEFINE_PER_CPU(u32, debug_stack_use_ctr);
+DEFINE_PER_CPU(u32, debug_stack_use_ctr);

 void debug_stack_set_zero(void)
 {
@@ -1156,8 +1156,14 @@ void debug_stack_reset(void)
 {
 	if (WARN_ON(!this_cpu_read(debug_stack_use_ctr)))
 		return;
-	if (this_cpu_dec_return(debug_stack_use_ctr) == 0)
-		load_idt((const struct desc_ptr *)&idt_descr);
+	if (this_cpu_dec_return(debug_stack_use_ctr) == 0) {
+#ifdef CONFIG_TRACING
+		if (this_cpu_read(trace_idt_in_use))
+			load_idt((const struct desc_ptr *)&trace_idt_descr);
+		else
+#endif
+			load_idt((const struct desc_ptr *)&idt_descr);
+	}
 }

 #else	/* CONFIG_X86_64 */
diff --git a/arch/x86/kernel/cpu/mcheck/therm_throt.c b/arch/x86/kernel/cpu/mcheck/therm_throt.c
index 47a1870..e7aa7fc 100644
--- a/arch/x86/kernel/cpu/mcheck/therm_throt.c
+++ b/arch/x86/kernel/cpu/mcheck/therm_throt.c
@@ -29,6 +29,7 @@
 #include <asm/idle.h>
 #include <asm/mce.h>
 #include <asm/msr.h>
+#include <asm/trace/irq_vectors.h>

 /* How long to wait between reporting thermal events */
 #define CHECK_INTERVAL		(300 * HZ)
@@ -389,6 +390,19 @@ asmlinkage void smp_thermal_interrupt(struct pt_regs *regs)
 	ack_APIC_irq();
 }

+asmlinkage void smp_trace_thermal_interrupt(struct pt_regs *regs)
+{
+	irq_enter();
+	exit_idle();
+	trace_thermal_apic_entry(THERMAL_APIC_VECTOR);
+	inc_irq_stat(irq_thermal_count);
+	smp_thermal_vector();
+	trace_thermal_apic_exit(THERMAL_APIC_VECTOR);
+	irq_exit();
+	/* Ack only at the end to avoid potential reentry */
+	ack_APIC_irq();
+}
+
 /* Thermal monitoring depends on APIC, ACPI and clock modulation */
 static int intel_thermal_supported(struct cpuinfo_x86 *c)
 {
diff --git a/arch/x86/kernel/cpu/mcheck/threshold.c b/arch/x86/kernel/cpu/mcheck/threshold.c
index aa578ca..0cbef99 100644
--- a/arch/x86/kernel/cpu/mcheck/threshold.c
+++ b/arch/x86/kernel/cpu/mcheck/threshold.c
@@ -8,6 +8,7 @@
 #include <asm/apic.h>
 #include <asm/idle.h>
 #include <asm/mce.h>
+#include <asm/trace/irq_vectors.h>

 static void default_threshold_interrupt(void)
 {
@@ -27,3 +28,16 @@ asmlinkage void smp_threshold_interrupt(void)
 	/* Ack only at the end to avoid potential reentry */
 	ack_APIC_irq();
 }
+
+asmlinkage void smp_trace_threshold_interrupt(void)
+{
+	irq_enter();
+	exit_idle();
+	trace_threshold_apic_entry(THRESHOLD_APIC_VECTOR);
+	inc_irq_stat(irq_threshold_count);
+	mce_threshold_vector();
+	trace_threshold_apic_exit(THRESHOLD_APIC_VECTOR);
+	irq_exit();
+	/* Ack only at the end to avoid potential reentry */
+	ack_APIC_irq();
+}
diff --git a/arch/x86/kernel/entry_32.S b/arch/x86/kernel/entry_32.S
index 8f3e2de..2cfbc3a 100644
--- a/arch/x86/kernel/entry_32.S
+++ b/arch/x86/kernel/entry_32.S
@@ -801,7 +801,17 @@ ENTRY(name)				\
 	CFI_ENDPROC;			\
 ENDPROC(name)

-#define BUILD_INTERRUPT(name, nr)	BUILD_INTERRUPT3(name, nr, smp_##name)
+
+#ifdef CONFIG_TRACING
+#define TRACE_BUILD_INTERRUPT(name, nr)		\
+	BUILD_INTERRUPT3(trace_##name, nr, smp_trace_##name)
+#else
+#define TRACE_BUILD_INTERRUPT(name, nr)
+#endif
+
+#define BUILD_INTERRUPT(name, nr) \
+	BUILD_INTERRUPT3(name, nr, smp_##name); \
+	TRACE_BUILD_INTERRUPT(name, nr)

 /* The include is where all of the SMP etc. interrupts come from */
 #include <asm/entry_arch.h>
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index c1d01e6..4570477 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -1138,7 +1138,7 @@ END(common_interrupt)
 /*
  * APIC interrupts.
  */
-.macro apicinterrupt num sym do_sym
+.macro apicinterrupt3 num sym do_sym
 ENTRY(\sym)
 	INTR_FRAME
 	ASM_CLAC
@@ -1150,15 +1150,32 @@ ENTRY(\sym)
 END(\sym)
 .endm

+#ifdef CONFIG_TRACING
+#define trace(sym) trace_##sym
+#define smp_trace(sym) smp_trace_##sym
+
+.macro trace_apicinterrupt num sym
+apicinterrupt3 \num trace(\sym) smp_trace(\sym)
+.endm
+#else
+.macro trace_apicinterrupt num sym do_sym
+.endm
+#endif
+
+.macro apicinterrupt num sym do_sym
+apicinterrupt3 \num \sym \do_sym
+trace_apicinterrupt \num \sym
+.endm
+
 #ifdef CONFIG_SMP
-apicinterrupt IRQ_MOVE_CLEANUP_VECTOR \
+apicinterrupt3 IRQ_MOVE_CLEANUP_VECTOR \
 	irq_move_cleanup_interrupt smp_irq_move_cleanup_interrupt
-apicinterrupt REBOOT_VECTOR \
+apicinterrupt3 REBOOT_VECTOR \
 	reboot_interrupt smp_reboot_interrupt
 #endif

 #ifdef CONFIG_X86_UV
-apicinterrupt UV_BAU_MESSAGE \
+apicinterrupt3 UV_BAU_MESSAGE \
 	uv_bau_message_intr1 uv_bau_message_interrupt
 #endif
 apicinterrupt LOCAL_TIMER_VECTOR \
@@ -1446,13 +1463,13 @@ ENTRY(xen_failsafe_callback)
 	CFI_ENDPROC
 END(xen_failsafe_callback)

-apicinterrupt HYPERVISOR_CALLBACK_VECTOR \
+apicinterrupt3 HYPERVISOR_CALLBACK_VECTOR \
 	xen_hvm_callback_vector xen_evtchn_do_upcall

 #endif /* CONFIG_XEN */

 #if IS_ENABLED(CONFIG_HYPERV)
-apicinterrupt HYPERVISOR_CALLBACK_VECTOR \
+apicinterrupt3 HYPERVISOR_CALLBACK_VECTOR \
 	hyperv_callback_vector hyperv_vector_handler
 #endif /* CONFIG_HYPERV */

diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
index 6859e96..e827e67 100644
--- a/arch/x86/kernel/head_64.S
+++ b/arch/x86/kernel/head_64.S
@@ -518,6 +518,12 @@ ENTRY(idt_table)
 ENTRY(nmi_idt_table)
 	.skip IDT_ENTRIES * 16

+#ifdef CONFIG_TRACING
+	.align L1_CACHE_BYTES
+ENTRY(trace_idt_table)
+	.skip IDT_ENTRIES * 16
+#endif
+
 	__PAGE_ALIGNED_BSS
 NEXT_PAGE(empty_zero_page)
 	.skip PAGE_SIZE
diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c
index e4595f1..216bec1 100644
--- a/arch/x86/kernel/irq.c
+++ b/arch/x86/kernel/irq.c
@@ -17,6 +17,7 @@
 #include <asm/idle.h>
 #include <asm/mce.h>
 #include <asm/hw_irq.h>
+#include <asm/trace/irq_vectors.h>

 atomic_t irq_err_count;

@@ -228,6 +229,28 @@ void smp_x86_platform_ipi(struct pt_regs *regs)
 	set_irq_regs(old_regs);
 }

+void smp_trace_x86_platform_ipi(struct pt_regs *regs)
+{
+	struct pt_regs *old_regs = set_irq_regs(regs);
+
+	ack_APIC_irq();
+
+	irq_enter();
+
+	exit_idle();
+
+	trace_x86_platform_ipi_entry(X86_PLATFORM_IPI_VECTOR);
+	inc_irq_stat(x86_platform_ipis);
+
+	if (x86_platform_ipi_callback)
+		x86_platform_ipi_callback();
+
+	trace_x86_platform_ipi_exit(X86_PLATFORM_IPI_VECTOR);
+	irq_exit();
+
+	set_irq_regs(old_regs);
+}
+
 EXPORT_SYMBOL_GPL(vector_used_by_percpu_irq);

 #ifdef CONFIG_HOTPLUG_CPU
diff --git a/arch/x86/kernel/irq_work.c b/arch/x86/kernel/irq_work.c
index ca8f703..09e6262 100644
--- a/arch/x86/kernel/irq_work.c
+++ b/arch/x86/kernel/irq_work.c
@@ -8,6 +8,7 @@
 #include <linux/irq_work.h>
 #include <linux/hardirq.h>
 #include <asm/apic.h>
+#include <asm/trace/irq_vectors.h>

 void smp_irq_work_interrupt(struct pt_regs *regs)
 {
@@ -18,6 +19,17 @@ void smp_irq_work_interrupt(struct pt_regs *regs)
 	irq_exit();
 }

+void smp_trace_irq_work_interrupt(struct pt_regs *regs)
+{
+	irq_enter();
+	ack_APIC_irq();
+	trace_irq_work_entry(IRQ_WORK_VECTOR);
+	inc_irq_stat(apic_irq_work_irqs);
+	irq_work_run();
+	trace_irq_work_exit(IRQ_WORK_VECTOR);
+	irq_exit();
+}
+
 void arch_irq_work_raise(void)
 {
 #ifdef CONFIG_X86_LOCAL_APIC
diff --git a/arch/x86/kernel/smp.c b/arch/x86/kernel/smp.c
index 48d2b7d..aad58af 100644
--- a/arch/x86/kernel/smp.c
+++ b/arch/x86/kernel/smp.c
@@ -30,6 +30,7 @@
 #include <asm/proto.h>
 #include <asm/apic.h>
 #include <asm/nmi.h>
+#include <asm/trace/irq_vectors.h>
 /*
  *	Some notes on x86 processor bugs affecting SMP operation:
  *
@@ -259,6 +260,18 @@ void smp_reschedule_interrupt(struct pt_regs *regs)
 	 */
 }

+void smp_trace_reschedule_interrupt(struct pt_regs *regs)
+{
+	ack_APIC_irq();
+	trace_reschedule_entry(RESCHEDULE_VECTOR);
+	inc_irq_stat(irq_resched_count);
+	scheduler_ipi();
+	trace_reschedule_exit(RESCHEDULE_VECTOR);
+	/*
+	 * KVM uses this interrupt to force a cpu out of guest mode
+	 */
+}
+
 void smp_call_function_interrupt(struct pt_regs *regs)
 {
 	ack_APIC_irq();
@@ -268,6 +281,17 @@ void smp_call_function_interrupt(struct pt_regs *regs)
 	irq_exit();
 }

+void smp_trace_call_function_interrupt(struct pt_regs *regs)
+{
+	ack_APIC_irq();
+	irq_enter();
+	trace_call_function_entry(CALL_FUNCTION_VECTOR);
+	generic_smp_call_function_interrupt();
+	inc_irq_stat(irq_call_count);
+	trace_call_function_exit(CALL_FUNCTION_VECTOR);
+	irq_exit();
+}
+
 void smp_call_function_single_interrupt(struct pt_regs *regs)
 {
 	ack_APIC_irq();
@@ -277,6 +301,17 @@ void smp_call_function_single_interrupt(struct pt_regs *regs)
 	irq_exit();
 }

+void smp_trace_call_function_single_interrupt(struct pt_regs *regs)
+{
+	ack_APIC_irq();
+	irq_enter();
+	trace_call_function_single_entry(CALL_FUNCTION_SINGLE_VECTOR);
+	generic_smp_call_function_single_interrupt();
+	inc_irq_stat(irq_call_count);
+	trace_call_function_single_exit(CALL_FUNCTION_SINGLE_VECTOR);
+	irq_exit();
+}
+
 static int __init nonmi_ipi_setup(char *str)
 {
 	smp_no_nmi_ipi = true;
diff --git a/arch/x86/kernel/tracepoint.c b/arch/x86/kernel/tracepoint.c
new file mode 100644
index 0000000..3403dc3
--- /dev/null
+++ b/arch/x86/kernel/tracepoint.c
@@ -0,0 +1,71 @@
+/*
+ * Code for supporting irq vector tracepoints.
+ *
+ * Copyright (C) 2013 Seiji Aguchi <sei...@hd...>
+ *
+ */
+#include <asm/hw_irq.h>
+#include <asm/desc.h>
+
+struct desc_ptr trace_idt_descr = { NR_VECTORS * 16 - 1,
+				(unsigned long) trace_idt_table };
+
+#ifndef CONFIG_X86_64
+gate_desc trace_idt_table[NR_VECTORS] __page_aligned_data
+					= { { { { 0, 0 } } }, };
+#endif
+
+static int trace_irq_vector_refcount;
+static DEFINE_MUTEX(irq_vector_mutex);
+DEFINE_PER_CPU(u32, trace_idt_in_use);
+
+static void switch_to_trace_idt(void *arg)
+{
+
+	this_cpu_inc(trace_idt_in_use);
+	load_idt(&trace_idt_descr);
+
+	return;
+}
+
+static void restore_original_idt(void *arg)
+{
+	if (WARN_ON(!this_cpu_read(trace_idt_in_use)))
+		return;
+	this_cpu_dec(trace_idt_in_use);
+
+#ifdef CONFIG_X86_64
+	if (this_cpu_read(debug_stack_use_ctr))
+		load_idt(&nmi_idt_descr);
+	else
+#endif
+		load_idt(&idt_descr);
+	return;
+}
+
+void trace_irq_vector_regfunc(void)
+{
+	mutex_lock(&irq_vector_mutex);
+	if (!trace_irq_vector_refcount) {
+		smp_call_function(switch_to_trace_idt, NULL, 0);
+		local_irq_disable();
+		switch_to_trace_idt(NULL);
+		local_irq_enable();
+	}
+	trace_irq_vector_refcount++;
+	mutex_unlock(&irq_vector_mutex);
+}
+
+void trace_irq_vector_unregfunc(void)
+{
+	mutex_lock(&irq_vector_mutex);
+	trace_irq_vector_refcount--;
+	if (!trace_irq_vector_refcount) {
+		smp_call_function(restore_original_idt, NULL, 0);
+		local_irq_disable();
+		restore_original_idt(NULL);
+		local_irq_enable();
+	}
+	mutex_unlock(&irq_vector_mutex);
+}
+
diff --git a/include/xen/events.h b/include/xen/events.h
index c6bfe01..9216d07 100644
--- a/include/xen/events.h
+++ b/include/xen/events.h
@@ -76,6 +76,9 @@ unsigned irq_from_evtchn(unsigned int evtchn);

 /* Xen HVM evtchn vector callback */
 void xen_hvm_callback_vector(void);
+#ifdef CONFIG_TRACING
+#define trace_xen_hvm_callback_vector xen_hvm_callback_vector
+#endif
 extern int xen_have_vector_callback;
 int xen_set_callback_via(uint64_t via);
 void xen_evtchn_do_upcall(struct pt_regs *regs);
-- 1.7.1

[Dle-develop] [PATCH v11 1/3] tracing: Add DEFINE_EVENT_FN() macro

[Seiji A. <sei...@hd...>]

Each TRACE_EVENT() adds several helper functions. If two or more trace events
share the same structure and print format, they can also share most of these
helper functions and save a lot of space from duplicate code. This is why the
DECLARE_EVENT_CLASS() and DEFINE_EVENT() were created.

Some events require a trigger to be called at registering and unregistering of
the event and to do so they use TRACE_EVENT_FN().

If multiple events require a trigger, they currently have no choice but to use
TRACE_EVENT_FN() as there's no DEFINE_EVENT_FN() available. This unfortunately
causes a lot of wasted duplicate code created.

By adding a DEFINE_EVENT_FN(), these events can still use a
DECLARE_EVENT_CLASS() and then define their own triggers.

Signed-off-by: Steven Rostedt <ro...@go...>
Signed-off-by: Seiji Aguchi <sei...@hd...>
---
 include/linux/tracepoint.h   |    2 ++
 include/trace/define_trace.h |    5 +++++
 include/trace/ftrace.h       |    4 ++++
 3 files changed, 11 insertions(+), 0 deletions(-)

diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h
index 2f322c3..9bf59e5 100644
--- a/include/linux/tracepoint.h
+++ b/include/linux/tracepoint.h
@@ -378,6 +378,8 @@ static inline void tracepoint_synchronize_unregister(void)
 #define DECLARE_EVENT_CLASS(name, proto, args, tstruct, assign, print)
 #define DEFINE_EVENT(template, name, proto, args)		\
 	DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
+#define DEFINE_EVENT_FN(template, name, proto, args, reg, unreg)\
+	DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
 #define DEFINE_EVENT_PRINT(template, name, proto, args, print)	\
 	DECLARE_TRACE(name, PARAMS(proto), PARAMS(args))
 #define DEFINE_EVENT_CONDITION(template, name, proto,		\
diff --git a/include/trace/define_trace.h b/include/trace/define_trace.h
index 1905ca8..02e1003 100644
--- a/include/trace/define_trace.h
+++ b/include/trace/define_trace.h
@@ -44,6 +44,10 @@
 #define DEFINE_EVENT(template, name, proto, args) \
 	DEFINE_TRACE(name)
 
+#undef DEFINE_EVENT_FN
+#define DEFINE_EVENT_FN(template, name, proto, args, reg, unreg) \
+	DEFINE_TRACE_FN(name, reg, unreg)
+
 #undef DEFINE_EVENT_PRINT
 #define DEFINE_EVENT_PRINT(template, name, proto, args, print)	\
 	DEFINE_TRACE(name)
@@ -91,6 +95,7 @@
 #undef TRACE_EVENT_CONDITION
 #undef DECLARE_EVENT_CLASS
 #undef DEFINE_EVENT
+#undef DEFINE_EVENT_FN
 #undef DEFINE_EVENT_PRINT
 #undef DEFINE_EVENT_CONDITION
 #undef TRACE_HEADER_MULTI_READ
diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h
index 40dc5e8..7bab676 100644
--- a/include/trace/ftrace.h
+++ b/include/trace/ftrace.h
@@ -71,6 +71,10 @@
 	static struct ftrace_event_call	__used		\
 	__attribute__((__aligned__(4))) event_##name
 
+#undef DEFINE_EVENT_FN
+#define DEFINE_EVENT_FN(template, name, proto, args, reg, unreg)	\
+	DEFINE_EVENT(template, name, PARAMS(proto), PARAMS(args))
+
 #undef DEFINE_EVENT_PRINT
 #define DEFINE_EVENT_PRINT(template, name, proto, args, print)	\
 	DEFINE_EVENT(template, name, PARAMS(proto), PARAMS(args))
-- 1.7.1

[Dle-develop] [PATCH v11 0/3]trace, x86: irq vector tracepoint support

[Seiji A. <sei...@hd...>]

Change log
 v10 -> v11
 - Rebase to 3.9-rc2
 - Add a modification for hyperv_callback vector. (patch 2/3)
 - Change a way to switch idt to check the table in use instead of saving/restoring it,
   because saving/restoring functions will break if we have to add another one. (patch 2/3)

 v9 -> v10
 - Add an explanation the reason why tracepoints has to place inside irq enter/exit handling. (patch 3/3)

 v8 -> v9
 - Rebase to 3.8-rc6
 - Add Steven's email address at the top of the message and 
   move my signed-off-by below Steven's one because it is
   originally created by Steven. (patch 1/3)
 - Introduce a irq_vector_mutex to avoid a race at registering/unregistering
   time. (patch 2/3)
 - Use a per_cpu data to orig_idt_descr because IDT descritor is needed to each cpu
   and the appropriate data type is per_cpu data. It is suggested by Steven.
   (patch 2/3)

 v7 -> v8
 - Rebase to 3.8-rc4
 - Add a patch 1 introducing DEFINE_EVENT_FN() macro.
 - Rename original patches 1 and 2 to 2 and 3.
 - Change a definition of tracepoint to use DEFINE_EVENT_FN(). (patch 2)
 - Change alloc_intr_gate() to use do{}while(0) to avoid a warning 
   of checkpatch.pl. (patch 2)
 - Move entering_irq()/exiting_irq() to arch/x86/include/asm/apic.h (patch 3)

 v6 -> v7
 - Divide into two patches to make a code review easier.
   Summery of each patch is as follows.
    - Patch 1/2
      - Add an irq_vector tracing infrastructure.
      - Create idt_table for tracing. It is refactored to avoid duplicating
        existing logic.
      - Duplicate new irq handlers inserted tracepoints.

    - Patch 2/2
      - Share a common logic among irq handlers to make them
        manageable and readable.

 v5 -> v6
 - Rebased to 3.7

 v4 -> v5
 - Rebased to 3.6.0

 - Introduce a logic switching IDT at enabling/disabling TP time 
   so that a time penalty makes a zero when tracepoints are disabled.
   This IDT is created only when CONFIG_TRACEPOINTS is enabled.

 - Remove arch_irq_vector_entry/exit and add followings again
   so that we can add each tracepoint in a generic way.
   - error_apic_vector
   - thermal_apic_vector
   - threshold_apic_vector
   - spurious_apic_vector
   - x86_platform_ipi_vector

 - Drop nmi tracepoints to begin with apic interrupts and discuss a logic switching
   IDT first.

 - Move irq_vectors.h in the directory of arch/x86/include/asm/trace because
   I'm not sure if a logic switching IDT is sharable with other architectures.

 v3 -> v4
 - Add a latency measurement of each tracepoint
 - Rebased to 3.6-rc6

 v2 -> v3
 - Remove an invalidate_tlb_vector event because it was replaced by a call function vector
   in a following commit.
   http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=commit;h=52aec3308db85f4e9f5c8b9f5dc4fbd0138c6fa4

 v1 -> v2
 - Modify variable name from irq to vector.
 - Merge arch-specific tracepoints below to an arch_irq_vector_entry/exit.
   - error_apic_vector
   - thermal_apic_vector
   - threshold_apic_vector
   - spurious_apic_vector
   - x86_platform_ipi_vector

[Purpose of this patch]

As Vaibhav explained in the thread below, tracepoints for irq vectors are useful.

http://www.spinics.net/lists/mm-commits/msg85707.html

<snip>
The current interrupt traces from irq_handler_entry and irq_handler_exit provide when an interrupt is handled.  
They provide good data about when the system has switched to kernel space and how it affects the currently running processes.

There are some IRQ vectors which trigger the system into kernel space, which are not handled in generic IRQ handlers.  
Tracing such events gives us the information about IRQ interaction with other system events.

The trace also tells where the system is spending its time.  We want to know which cores are handling interrupts and 
how they are affecting other processes in the system.  Also, the trace provides information about when the cores are 
idle and which interrupts are changing that state.
<snip>

On the other hand, my usecase is tracing just local timer event and getting a value of instruction pointer.

I suggested to add an argument local timer event to get instruction pointer before.
But there is another way to get it with external module like systemtap.
So, I don't need to add any argument to irq vector tracepoints now.

[Patch Description]

Vaibhav's patch shared a trace point ,irq_vector_entry/irq_vector_exit, in all events.
But there is an above use case to trace specific irq_vector rather than tracing all events.
In this case, we are concerned about overhead due to unwanted events.

This patch adds following tracepoints instead of introducing irq_vector_entry/exit.
so that we can enable them independently.
   - local_timer_vector
   - reschedule_vector
   - call_function_vector
   - call_function_single_vector 
   - irq_work_entry_vector
   - error_apic_vector
   - thermal_apic_vector
   - threshold_apic_vector
   - spurious_apic_vector
   - x86_platform_ipi_vector

Please see descriptions in each patch.

Seiji Aguchi (2):
  trace,x86: add x86 irq vector tracepoints
  trace,x86: code-sharing between non-trace and trace irq handlers

Steven Rostedt (1):
  tracing: Add DEFINE_EVENT_FN() macro

 arch/x86/include/asm/apic.h              |   27 +++++
 arch/x86/include/asm/desc.h              |   36 +++++++-
 arch/x86/include/asm/entry_arch.h        |    5 +-
 arch/x86/include/asm/hw_irq.h            |   16 +++
 arch/x86/include/asm/mshyperv.h          |    1 +
 arch/x86/include/asm/trace/irq_vectors.h |  159 ++++++++++++++++++++++++++++++
 arch/x86/kernel/Makefile                 |    1 +
 arch/x86/kernel/apic/apic.c              |   71 +++++++++++---
 arch/x86/kernel/cpu/common.c             |   12 ++-
 arch/x86/kernel/cpu/mcheck/therm_throt.c |   24 ++++-
 arch/x86/kernel/cpu/mcheck/threshold.c   |   24 ++++-
 arch/x86/kernel/entry_32.S               |   12 ++-
 arch/x86/kernel/entry_64.S               |   29 +++++-
 arch/x86/kernel/head_64.S                |    6 +
 arch/x86/kernel/irq.c                    |   31 ++++--
 arch/x86/kernel/irq_work.c               |   24 ++++-
 arch/x86/kernel/smp.c                    |   65 +++++++++++--
 arch/x86/kernel/tracepoint.c             |   71 +++++++++++++
 include/linux/tracepoint.h               |    2 +
 include/trace/define_trace.h             |    5 +
 include/trace/ftrace.h                   |    4 +
 include/xen/events.h                     |    3 +
 22 files changed, 570 insertions(+), 58 deletions(-)
 create mode 100644 arch/x86/include/asm/trace/irq_vectors.h
 create mode 100644 arch/x86/kernel/tracepoint.c

Re: [Dle-develop] [PATCH v2] Add option to mlock qemu and guest memory

[Satoru M. <sat...@hd...>]

Ping.

Can anyone else review this patch?

Regards,
Satoru

On 03/12/2013 05:40 AM, Paolo Bonzini wrote:
> Il 14/02/2013 21:21, Satoru Moriya ha scritto:
>> We have some plans to migrate legacy enterprise systems which require 
>> low latency (10 msec order) to kvm virtualized environment. In our 
>> usecase, the system runs with other untrusted guests and so locking 
>> memory which is used by the system is needed to avoid latency impacts 
>> from other guests' memory activity.
>>
>> ChangeLog:
>> v2
>>  - Change the option name from -mlock to -realtime mlock=on|off
>>  - Rebase qemu version 1.3.91
>>  - Update patch description
>>
>> ---
>> In certain scenario, latency induced by paging is significant and 
>> memory locking is needed. Also, in the scenario with untrusted 
>> guests, latency improvement due to mlock is desired.
>>
>> This patch introduces a following new option to mlock guest and qemu 
>> memory:
>>
>> -realtime mlock=on|off
>>
>> Signed-off-by: Satoru Moriya <sat...@hd...>
> 
> Reviewed-by: Paolo Bonzini <pbo...@re...>
> 
> As a follow up it would be nice to move -mem-prealloc/-mem-path under 
> -realtime as well.
> 
> Paolo
> 
>> ---
>>  include/sysemu/os-posix.h |  1 +
>>  include/sysemu/os-win32.h |  1 +
>>  os-posix.c                |  8 ++++++++
>>  qemu-options.hx           | 13 +++++++++++++
>>  vl.c                      | 31 +++++++++++++++++++++++++++++++
>>  5 files changed, 54 insertions(+)
>>
>> diff --git a/include/sysemu/os-posix.h b/include/sysemu/os-posix.h 
>> index 7f198e4..2f2ead6 100644
>> --- a/include/sysemu/os-posix.h
>> +++ b/include/sysemu/os-posix.h
>> @@ -31,6 +31,7 @@ void os_set_proc_name(const char *s);  void 
>> os_setup_signal_handling(void);  void os_daemonize(void);  void 
>> os_setup_post(void);
>> +void os_mlock(void);
>>  
>>  typedef struct timeval qemu_timeval;  #define qemu_gettimeofday(tp) 
>> gettimeofday(tp, NULL) diff --git a/include/sysemu/os-win32.h 
>> b/include/sysemu/os-win32.h index bf9edeb..a74ca13 100644
>> --- a/include/sysemu/os-win32.h
>> +++ b/include/sysemu/os-win32.h
>> @@ -80,6 +80,7 @@ static inline void os_daemonize(void) {}  static 
>> inline void os_setup_post(void) {}  void os_set_line_buffering(void);  
>> static inline void os_set_proc_name(const char *dummy) {}
>> +static inline void os_mlock(void) {}
>>  
>>  #if !defined(EPROTONOSUPPORT)
>>  # define EPROTONOSUPPORT EINVAL
>> diff --git a/os-posix.c b/os-posix.c
>> index 5c64518..1304b0e 100644
>> --- a/os-posix.c
>> +++ b/os-posix.c
>> @@ -363,3 +363,11 @@ bool is_daemonized(void)  {
>>      return daemonize;
>>  }
>> +
>> +void os_mlock(void)
>> +{
>> +    if (mlockall(MCL_CURRENT | MCL_FUTURE)) {
>> +        perror("mlockall");
>> +        exit(1);
>> +    }
>> +}
>> diff --git a/qemu-options.hx b/qemu-options.hx index 9d7131a..843fcb4 
>> 100644
>> --- a/qemu-options.hx
>> +++ b/qemu-options.hx
>> @@ -2464,6 +2464,19 @@ STEXI
>>  Do not start CPU at startup (you must type 'c' in the monitor).
>>  ETEXI
>>  
>> +DEF("realtime", HAS_ARG, QEMU_OPTION_realtime,
>> +    "-realtime [mlock=on|off]\n"
>> +    "                run qemu with realtime features\n"
>> +    "                mlock=on|off controls mlock support (default: on)\n",
>> +    QEMU_ARCH_ALL)
>> +STEXI
>> +@item -realtime mlock=on|off
>> +@findex -realtime
>> +Run qemu with realtime features.
>> +mlocking qemu and guest memory can be enabled via @option{mlock=on} 
>> +(enabled by default).
>> +ETEXI
>> +
>>  DEF("gdb", HAS_ARG, QEMU_OPTION_gdb, \
>>      "-gdb dev        wait for gdb connection on 'dev'\n", QEMU_ARCH_ALL)
>>  STEXI
>> diff --git a/vl.c b/vl.c
>> index 1355f69..c16c8ad 100644
>> --- a/vl.c
>> +++ b/vl.c
>> @@ -491,6 +491,18 @@ static QemuOptsList qemu_object_opts = {
>>      },
>>  };
>>  
>> +static QemuOptsList qemu_realtime_opts = {
>> +    .name = "realtime",
>> +    .head = QTAILQ_HEAD_INITIALIZER(qemu_realtime_opts.head),
>> +    .desc = {
>> +        {
>> +            .name = "mlock",
>> +            .type = QEMU_OPT_BOOL,
>> +        },
>> +        { /* end of list */ }
>> +    },
>> +};
>> +
>>  const char *qemu_get_vm_name(void)
>>  {
>>      return qemu_name;
>> @@ -1384,6 +1396,17 @@ static void smp_parse(const char *optarg)
>>          max_cpus = smp_cpus;
>>  }
>>  
>> +static void configure_realtime(QemuOpts *opts) {
>> +    bool is_mlock;
>> +
>> +    is_mlock = qemu_opt_get_bool(opts, "mlock", true);
>> +
>> +    if (is_mlock) {
>> +        os_mlock();
>> +    }
>> +}
>> +
>>  /***********************************************************/
>>  /* USB devices */
>>  
>> @@ -2860,6 +2883,7 @@ int main(int argc, char **argv, char **envp)
>>      qemu_add_opts(&qemu_sandbox_opts);
>>      qemu_add_opts(&qemu_add_fd_opts);
>>      qemu_add_opts(&qemu_object_opts);
>> +    qemu_add_opts(&qemu_realtime_opts);
>>  
>>      runstate_init();
>>  
>> @@ -3806,6 +3830,13 @@ int main(int argc, char **argv, char **envp)
>>                      exit(1);
>>                  }
>>                  break;
>> +            case QEMU_OPTION_realtime:
>> +                opts = qemu_opts_parse(qemu_find_opts("realtime"), optarg, 0);
>> +                if (!opts) {
>> +                    exit(1);
>> +                }
>> +                configure_realtime(opts);
>> +                break;
>>              default:
>>                  os_parse_cmd_args(popt->index, optarg);
>>              }
>>
> 
> 

Re: [Dle-develop] [PATCH]Skip unnecessary WARN_ON in panic case

[Seiji A. <sei...@hd...>]

Thank you for giving me the feedback.

> 
> So it appears the problem occurs because the other CPUs are not offlined correctly, and still have pending work which may generate
> wakeup IPIs to them?

Right.

> 
> The fix would be to either offline them properly - or, if we don't want to do that to keep panicking simple, why do we mark them
> offline? They aren't really offline in a proper way.

To offline cpus properly, it should be done with threads like stop_machine().
But I don't think it is reasonable to kick the threads in panic case.
Therefore, I will make a patch keeping cpus online.
Also, to inform a panicked cpu that other cpus stopped surely,
 I will  introduce a new cpu_mask like cpu_stopped_mask.

Seiji

Re: [Dle-develop] [PATCH v2] Add option to mlock qemu and guest memory

[Paolo B. <pbo...@re...>]

Il 14/02/2013 21:21, Satoru Moriya ha scritto:
> We have some plans to migrate legacy enterprise systems which require
> low latency (10 msec order) to kvm virtualized environment. In our
> usecase, the system runs with other untrusted guests and so locking
> memory which is used by the system is needed to avoid latency
> impacts from other guests' memory activity.
> 
> ChangeLog:
> v2
>  - Change the option name from -mlock to -realtime mlock=on|off
>  - Rebase qemu version 1.3.91
>  - Update patch description
> 
> ---
> In certain scenario, latency induced by paging is significant and
> memory locking is needed. Also, in the scenario with untrusted
> guests, latency improvement due to mlock is desired.
> 
> This patch introduces a following new option to mlock guest and
> qemu memory:
> 
> -realtime mlock=on|off
> 
> Signed-off-by: Satoru Moriya <sat...@hd...>

Reviewed-by: Paolo Bonzini <pbo...@re...>

As a follow up it would be nice to move -mem-prealloc/-mem-path under
-realtime as well.

Paolo

> ---
>  include/sysemu/os-posix.h |  1 +
>  include/sysemu/os-win32.h |  1 +
>  os-posix.c                |  8 ++++++++
>  qemu-options.hx           | 13 +++++++++++++
>  vl.c                      | 31 +++++++++++++++++++++++++++++++
>  5 files changed, 54 insertions(+)
> 
> diff --git a/include/sysemu/os-posix.h b/include/sysemu/os-posix.h
> index 7f198e4..2f2ead6 100644
> --- a/include/sysemu/os-posix.h
> +++ b/include/sysemu/os-posix.h
> @@ -31,6 +31,7 @@ void os_set_proc_name(const char *s);
>  void os_setup_signal_handling(void);
>  void os_daemonize(void);
>  void os_setup_post(void);
> +void os_mlock(void);
>  
>  typedef struct timeval qemu_timeval;
>  #define qemu_gettimeofday(tp) gettimeofday(tp, NULL)
> diff --git a/include/sysemu/os-win32.h b/include/sysemu/os-win32.h
> index bf9edeb..a74ca13 100644
> --- a/include/sysemu/os-win32.h
> +++ b/include/sysemu/os-win32.h
> @@ -80,6 +80,7 @@ static inline void os_daemonize(void) {}
>  static inline void os_setup_post(void) {}
>  void os_set_line_buffering(void);
>  static inline void os_set_proc_name(const char *dummy) {}
> +static inline void os_mlock(void) {}
>  
>  #if !defined(EPROTONOSUPPORT)
>  # define EPROTONOSUPPORT EINVAL
> diff --git a/os-posix.c b/os-posix.c
> index 5c64518..1304b0e 100644
> --- a/os-posix.c
> +++ b/os-posix.c
> @@ -363,3 +363,11 @@ bool is_daemonized(void)
>  {
>      return daemonize;
>  }
> +
> +void os_mlock(void)
> +{
> +    if (mlockall(MCL_CURRENT | MCL_FUTURE)) {
> +        perror("mlockall");
> +        exit(1);
> +    }
> +}
> diff --git a/qemu-options.hx b/qemu-options.hx
> index 9d7131a..843fcb4 100644
> --- a/qemu-options.hx
> +++ b/qemu-options.hx
> @@ -2464,6 +2464,19 @@ STEXI
>  Do not start CPU at startup (you must type 'c' in the monitor).
>  ETEXI
>  
> +DEF("realtime", HAS_ARG, QEMU_OPTION_realtime,
> +    "-realtime [mlock=on|off]\n"
> +    "                run qemu with realtime features\n"
> +    "                mlock=on|off controls mlock support (default: on)\n",
> +    QEMU_ARCH_ALL)
> +STEXI
> +@item -realtime mlock=on|off
> +@findex -realtime
> +Run qemu with realtime features.
> +mlocking qemu and guest memory can be enabled via @option{mlock=on}
> +(enabled by default).
> +ETEXI
> +
>  DEF("gdb", HAS_ARG, QEMU_OPTION_gdb, \
>      "-gdb dev        wait for gdb connection on 'dev'\n", QEMU_ARCH_ALL)
>  STEXI
> diff --git a/vl.c b/vl.c
> index 1355f69..c16c8ad 100644
> --- a/vl.c
> +++ b/vl.c
> @@ -491,6 +491,18 @@ static QemuOptsList qemu_object_opts = {
>      },
>  };
>  
> +static QemuOptsList qemu_realtime_opts = {
> +    .name = "realtime",
> +    .head = QTAILQ_HEAD_INITIALIZER(qemu_realtime_opts.head),
> +    .desc = {
> +        {
> +            .name = "mlock",
> +            .type = QEMU_OPT_BOOL,
> +        },
> +        { /* end of list */ }
> +    },
> +};
> +
>  const char *qemu_get_vm_name(void)
>  {
>      return qemu_name;
> @@ -1384,6 +1396,17 @@ static void smp_parse(const char *optarg)
>          max_cpus = smp_cpus;
>  }
>  
> +static void configure_realtime(QemuOpts *opts)
> +{
> +    bool is_mlock;
> +
> +    is_mlock = qemu_opt_get_bool(opts, "mlock", true);
> +
> +    if (is_mlock) {
> +        os_mlock();
> +    }
> +}
> +
>  /***********************************************************/
>  /* USB devices */
>  
> @@ -2860,6 +2883,7 @@ int main(int argc, char **argv, char **envp)
>      qemu_add_opts(&qemu_sandbox_opts);
>      qemu_add_opts(&qemu_add_fd_opts);
>      qemu_add_opts(&qemu_object_opts);
> +    qemu_add_opts(&qemu_realtime_opts);
>  
>      runstate_init();
>  
> @@ -3806,6 +3830,13 @@ int main(int argc, char **argv, char **envp)
>                      exit(1);
>                  }
>                  break;
> +            case QEMU_OPTION_realtime:
> +                opts = qemu_opts_parse(qemu_find_opts("realtime"), optarg, 0);
> +                if (!opts) {
> +                    exit(1);
> +                }
> +                configure_realtime(opts);
> +                break;
>              default:
>                  os_parse_cmd_args(popt->index, optarg);
>              }
> 

Re: [Dle-develop] [PATCH]Skip unnecessary WARN_ON in panic case

[Ingo M. <mi...@ke...>]

* Seiji Aguchi <sei...@hd...> wrote:

> [Problem]
> 
> When kernel panics, unnecessary WARN_ON() may be printed after panic messages in a following scenario.
>  - A panicked cpu stops other cpus via smp_send_stop().
>  - Other cpus turn to be offline in stop_this_cpu().
>  - The panicked cpu enables interrupt.
>  - native_smp_send_reschedule() is called via a timer interrupt on the panicked cpu.
>  - The panicked cpu tries to send a reschedule IPI to other cpus
>  - The panicked cpu hits WARN_ON() because other cpus have already been offlined.
> 
> If an user has just a VGA console, panic messages may be missed because 
> they are floated outside a screen due to messages of the WARN_ON(). In 
> this case, it could be difficult to investigate the reason why a kernel 
> panicked.

So it appears the problem occurs because the other CPUs are not offlined 
correctly, and still have pending work which may generate wakeup IPIs to 
them?

The fix would be to either offline them properly - or, if we don't want to 
do that to keep panicking simple, why do we mark them offline? They aren't 
really offline in a proper way.

Thanks,

	Ingo

[Dle-develop] [PATCH]Skip unnecessary WARN_ON in panic case

[Seiji A. <sei...@hd...>]

[Problem]

When kernel panics, unnecessary WARN_ON() may be printed after panic messages in a following scenario.
 - A panicked cpu stops other cpus via smp_send_stop().
 - Other cpus turn to be offline in stop_this_cpu().
 - The panicked cpu enables interrupt.
 - native_smp_send_reschedule() is called via a timer interrupt on the panicked cpu.
 - The panicked cpu tries to send a reschedule IPI to other cpus
 - The panicked cpu hits WARN_ON() because other cpus have already been offlined.

If an user has just a VGA console, panic messages may be missed because they are floated outside a screen 
due to messages of the WARN_ON().
In this case, it could be difficult to investigate the reason why a kernel panicked.

Here is an actual result of the scenario above.

SysRq : Trigger a crash
BUG: unable to handle kernel NULL pointer dereference at           (null)
IP: [<ffffffff81346056>] sysrq_handle_crash+0x16/0x20
PGD 127f0c067 PUD 11c7fd067 PMD 0 
Oops: 0002 [#1] SMP 
Modules linked in: ebtable_nat ebtables xt_CHECKSUM iptable_mangle bridge autofs4 sunrpc 8021q garp stp llc cpufreq_ondemand ipt_REJECT nf_conntrack_ipv4 nf_defrag_ipv4 iptable_filter ip_tables ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables ipv6 vfat fat vhost_net macvtap macvlan tun uinput sg iTCO_wdt iTCO_vendor_support dcdbas acpi_cpufreq freq_table mperf coretemp kvm_intel kvm crc32c_intel microcode pcspkr i7core_edac edac_core lpc_ich mfd_core bnx2 ext4(F) mbcache(F) jbd2(F) sr_mod(F) cdrom(F) sd_mod(F) crc_t10dif(F) pata_acpi(F) ata_generic(F) ata_piix(F) dm_mirror(F) dm_region_hash(F) dm_log(F) dm_mod(F)
CPU 2 
Pid: 4225, comm: bash Tainted: GF            3.9.0-rc1+ #9 Dell Inc. PowerEdge T310/02P9X9
RIP: 0010:[<ffffffff81346056>]  [<ffffffff81346056>] sysrq_handle_crash+0x16/0x20
RSP: 0018:ffff8801298b1e18  EFLAGS: 00010096
RAX: 000000000000000f RBX: 0000000000000063 RCX: ffff88013f24fb10
RDX: 0000000000000000 RSI: ffff88013f24df08 RDI: 0000000000000063
RBP: ffff8801298b1e18 R08: 0000000000000003 R09: 00000000000115e4
R10: 0000000000000371 R11: 0000000000000372 R12: ffffffff81aa5a40
R13: 0000000000000286 R14: 0000000000000007 R15: 0000000000000000
FS:  00007fcaed1b1700(0000) GS:ffff88013f240000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000128d91000 CR4: 00000000000007e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process bash (pid: 4225, threadinfo ffff8801298b0000, task ffff880128d15580)
Stack:
 ffff8801298b1e58 ffffffff81346969 ffff8801298b1f38 0000000000000002
 ffff880129605e80 00007fcaed1c2000 0000000000000002 fffffffffffffffb
 ffff8801298b1e88 ffffffff81346a1a ffff8801298b1eb8 00007fcaed1c2000
Call Trace:
 [<ffffffff81346969>] __handle_sysrq+0x129/0x190
 [<ffffffff81346a1a>] write_sysrq_trigger+0x4a/0x50
 [<ffffffff811e4cb9>] proc_reg_write+0x79/0xb0
 [<ffffffff8117f104>] vfs_write+0xb4/0x130
 [<ffffffff8117f8cf>] sys_write+0x5f/0xa0
 [<ffffffff81570a19>] system_call_fastpath+0x16/0x1b
Code: 48 81 c7 08 08 00 00 e8 c9 1b 22 00 31 c0 e9 62 ff ff ff 90 90 55 48 89 e5 66 66 66 66 90 c7 05 cd 02 9f 00 01 00 00 00 0f ae f8 <c6> 04 25 00 00 00 00 01 c9 c3 55 48 89 e5 66 66 66 66 90 8d 47 
RIP  [<ffffffff81346056>] sysrq_handle_crash+0x16/0x20
 RSP <ffff8801298b1e18>
CR2: 0000000000000000
---[ end trace b3d5243c59d80623 ]---
Kernel panic - not syncing: Fatal exception
------------[ cut here ]------------
WARNING: at arch/x86/kernel/smp.c:123 native_smp_send_reschedule+0x5c/0x60()
Hardware name: PowerEdge T310
Modules linked in: ebtable_nat ebtables xt_CHECKSUM iptable_mangle bridge autofs4 sunrpc 8021q garp stp llc cpufreq_ondemand ipt_REJECT nf_conntrack_ipv4 nf_defrag_ipv4 iptable_filter ip_tables ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables ipv6 vfat fat vhost_net macvtap macvlan tun uinput sg iTCO_wdt iTCO_vendor_support dcdbas acpi_cpufreq freq_table mperf coretemp kvm_intel kvm crc32c_intel microcode pcspkr i7core_edac edac_core lpc_ich mfd_core bnx2 ext4(F) mbcache(F) jbd2(F) sr_mod(F) cdrom(F) sd_mod(F) crc_t10dif(F) pata_acpi(F) ata_generic(F) ata_piix(F) dm_mirror(F) dm_region_hash(F) dm_log(F) dm_mod(F)
Pid: 4225, comm: bash Tainted: GF     D      3.9.0-rc1+ #9
Call Trace:
 <IRQ>  [<ffffffff81056daf>] warn_slowpath_common+0x7f/0xc0
 [<ffffffff81056e0a>] warn_slowpath_null+0x1a/0x20
 [<ffffffff8103918c>] native_smp_send_reschedule+0x5c/0x60
 [<ffffffff81092976>] trigger_load_balance+0x1c6/0x240
 [<ffffffff81089fff>] scheduler_tick+0x10f/0x140
 [<ffffffff81066f29>] update_process_times+0x69/0x80
 [<ffffffff810b1859>] tick_sched_handle+0x39/0x80
 [<ffffffff810b1a84>] tick_sched_timer+0x54/0x90
 [<ffffffff8107f1a3>] __run_hrtimer+0x83/0x1d0
 [<ffffffff810b1a30>] ? tick_nohz_handler+0xc0/0xc0
 [<ffffffff8107f576>] hrtimer_interrupt+0xf6/0x240
 [<ffffffff810435d6>] hpet_interrupt_handler+0x16/0x40
 [<ffffffff810e0f8d>] handle_irq_event_percpu+0x6d/0x210
 [<ffffffff8105f745>] ? __do_softirq+0x165/0x260
 [<ffffffff810e1172>] handle_irq_event+0x42/0x70
 [<ffffffff810e48c9>] handle_edge_irq+0x69/0x120
 [<ffffffff810164ac>] handle_irq+0x5c/0x150
 [<ffffffff8105f57b>] ? irq_enter+0x1b/0x80
 [<ffffffff8157265d>] do_IRQ+0x5d/0xe0
 [<ffffffff8156822d>] common_interrupt+0x6d/0x6d
 <EOI>  [<ffffffff815649d0>] ? panic+0x19c/0x1e4
 [<ffffffff8156492d>] ? panic+0xf9/0x1e4
 [<ffffffff81569114>] oops_end+0xe4/0x100
 [<ffffffff8104aa7e>] no_context+0x11e/0x1f0
 [<ffffffff8104ac7d>] __bad_area_nosemaphore+0x12d/0x230
 [<ffffffff8104adee>] bad_area+0x4e/0x60
 [<ffffffff8156c04e>] __do_page_fault+0x43e/0x490
 [<ffffffff81058b33>] ? call_console_drivers.clone.3+0xa3/0x110
 [<ffffffff81080f4f>] ? up+0x2f/0x50
 [<ffffffff81058404>] ? wake_up_klogd+0x34/0x40
 [<ffffffff81058f9d>] ? console_unlock+0x25d/0x290
 [<ffffffff8156c0ae>] do_page_fault+0xe/0x10
 [<ffffffff81568518>] page_fault+0x28/0x30
 [<ffffffff81346056>] ? sysrq_handle_crash+0x16/0x20
 [<ffffffff81346969>] __handle_sysrq+0x129/0x190
 [<ffffffff81346a1a>] write_sysrq_trigger+0x4a/0x50
 [<ffffffff811e4cb9>] proc_reg_write+0x79/0xb0
 [<ffffffff8117f104>] vfs_write+0xb4/0x130
 [<ffffffff8117f8cf>] sys_write+0x5f/0xa0
 [<ffffffff81570a19>] system_call_fastpath+0x16/0x1b
---[ end trace b3d5243c59d80624 ]---

[Solution]

Skip WARN_ON() when a panicked cpu which is set to stopping_cpu in
smp_send_stop() calls native_smp_send_reschedule().

Signed-off-by: Seiji Aguchi <sei...@hd...>
---
 arch/x86/kernel/smp.c |    6 +++++-
 1 files changed, 5 insertions(+), 1 deletions(-)

diff --git a/arch/x86/kernel/smp.c b/arch/x86/kernel/smp.c
index 48d2b7d..35168b1 100644
--- a/arch/x86/kernel/smp.c
+++ b/arch/x86/kernel/smp.c
@@ -120,7 +120,11 @@ static bool smp_no_nmi_ipi = false;
 static void native_smp_send_reschedule(int cpu)
 {
 	if (unlikely(cpu_is_offline(cpu))) {
-		WARN_ON(1);
+		/*
+		 * Skip WARN_ON() if cpu is stopping
+		 * to avoid printing spurious messages.
+		 */
+		WARN_ON(raw_smp_processor_id() != atomic_read(&stopping_cpu));
 		return;
 	}
 	apic->send_IPI_mask(cpumask_of(cpu), RESCHEDULE_VECTOR);
-- 
1.7.1

Re: [Dle-develop] [PATCH] qemu: fix wrong evaluation in qemuDomainSetMemoryParameters

[Peter K. <pk...@re...>]

On 03/04/13 18:27, Satoru Moriya wrote:
> 19c6ad9a (qemu: Refactor qemuDomainSetMemoryParameters) introduced
> a new macro, VIR_GET_LIMIT_PARAMETER(PARAM, VALUE). But if statement
> in the macro is not correct and so set_XXXX flags are set to false
> in the wrong. As a result, libvirt ignores all memtune parameters.
> This patch fixes the conditional expression to work correctly.
>
> Signed-off-by: Satoru Moriya <sat...@hd...>
> ---
>   src/qemu/qemu_driver.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
EW! :( Thanks for cathing this. ACK and will push soon.

Peter

Re: [Dle-develop] [libvirt] [PATCH] qemu: fix wrong evaluation in qemuDomainSetMemoryParameters

[Daniel P. B. <ber...@re...>]

On Mon, Mar 04, 2013 at 06:30:41PM +0100, Peter Krempa wrote:
> On 03/04/13 18:27, Satoru Moriya wrote:
> >19c6ad9a (qemu: Refactor qemuDomainSetMemoryParameters) introduced
> >a new macro, VIR_GET_LIMIT_PARAMETER(PARAM, VALUE). But if statement
> >in the macro is not correct and so set_XXXX flags are set to false
> >in the wrong. As a result, libvirt ignores all memtune parameters.
> >This patch fixes the conditional expression to work correctly.
> >
> >Signed-off-by: Satoru Moriya <sat...@hd...>
> >---
> >  src/qemu/qemu_driver.c | 2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> EW! :( Thanks for cathing this. ACK and will push soon.

Yep still time for the 1.0.3 release to include this/

Daniel
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[Dle-develop] [PATCH] qemu: fix wrong evaluation in qemuDomainSetMemoryParameters

[Satoru M. <sat...@hd...>]

19c6ad9a (qemu: Refactor qemuDomainSetMemoryParameters) introduced
a new macro, VIR_GET_LIMIT_PARAMETER(PARAM, VALUE). But if statement
in the macro is not correct and so set_XXXX flags are set to false
in the wrong. As a result, libvirt ignores all memtune parameters.
This patch fixes the conditional expression to work correctly.

Signed-off-by: Satoru Moriya <sat...@hd...>
---
 src/qemu/qemu_driver.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
index 7048ce9..42b8c77 100644
--- a/src/qemu/qemu_driver.c
+++ b/src/qemu/qemu_driver.c
@@ -7280,7 +7280,7 @@ qemuDomainSetMemoryParameters(virDomainPtr dom,
     }
 
 #define VIR_GET_LIMIT_PARAMETER(PARAM, VALUE)                                \
-    if ((rc = virTypedParamsGetULLong(params, nparams, PARAM, &VALUE) < 0))  \
+    if ((rc = virTypedParamsGetULLong(params, nparams, PARAM, &VALUE)) < 0)  \
         goto cleanup;                                                        \
                                                                              \
     if (rc == 1)                                                             \
--
1.7.11.7

Re: [Dle-develop] [PATCH v2] Add option to mlock qemu and guest memory

[Satoru M. <sat...@hd...>]

Ping?

On 02/14/2013 03:21 PM, Satoru Moriya wrote:
> We have some plans to migrate legacy enterprise systems which require 
> low latency (10 msec order) to kvm virtualized environment. In our 
> usecase, the system runs with other untrusted guests and so locking 
> memory which is used by the system is needed to avoid latency impacts 
> from other guests' memory activity.
> 
> ChangeLog:
> v2
>  - Change the option name from -mlock to -realtime mlock=on|off
>  - Rebase qemu version 1.3.91
>  - Update patch description
> 
> ---
> In certain scenario, latency induced by paging is significant and 
> memory locking is needed. Also, in the scenario with untrusted guests, 
> latency improvement due to mlock is desired.
> 
> This patch introduces a following new option to mlock guest and qemu 
> memory:
> 
> -realtime mlock=on|off
> 
> Signed-off-by: Satoru Moriya <sat...@hd...>
> ---
>  include/sysemu/os-posix.h |  1 +
>  include/sysemu/os-win32.h |  1 +
>  os-posix.c                |  8 ++++++++
>  qemu-options.hx           | 13 +++++++++++++
>  vl.c                      | 31 +++++++++++++++++++++++++++++++
>  5 files changed, 54 insertions(+)
> 
> diff --git a/include/sysemu/os-posix.h b/include/sysemu/os-posix.h 
> index 7f198e4..2f2ead6 100644
> --- a/include/sysemu/os-posix.h
> +++ b/include/sysemu/os-posix.h
> @@ -31,6 +31,7 @@ void os_set_proc_name(const char *s);  void 
> os_setup_signal_handling(void);  void os_daemonize(void);  void 
> os_setup_post(void);
> +void os_mlock(void);
>  
>  typedef struct timeval qemu_timeval;
>  #define qemu_gettimeofday(tp) gettimeofday(tp, NULL) diff --git 
> a/include/sysemu/os-win32.h b/include/sysemu/os-win32.h index 
> bf9edeb..a74ca13 100644
> --- a/include/sysemu/os-win32.h
> +++ b/include/sysemu/os-win32.h
> @@ -80,6 +80,7 @@ static inline void os_daemonize(void) {}  static 
> inline void os_setup_post(void) {}  void os_set_line_buffering(void);  
> static inline void os_set_proc_name(const char *dummy) {}
> +static inline void os_mlock(void) {}
>  
>  #if !defined(EPROTONOSUPPORT)
>  # define EPROTONOSUPPORT EINVAL
> diff --git a/os-posix.c b/os-posix.c
> index 5c64518..1304b0e 100644
> --- a/os-posix.c
> +++ b/os-posix.c
> @@ -363,3 +363,11 @@ bool is_daemonized(void)  {
>      return daemonize;
>  }
> +
> +void os_mlock(void)
> +{
> +    if (mlockall(MCL_CURRENT | MCL_FUTURE)) {
> +        perror("mlockall");
> +        exit(1);
> +    }
> +}
> diff --git a/qemu-options.hx b/qemu-options.hx index 9d7131a..843fcb4 
> 100644
> --- a/qemu-options.hx
> +++ b/qemu-options.hx
> @@ -2464,6 +2464,19 @@ STEXI
>  Do not start CPU at startup (you must type 'c' in the monitor).
>  ETEXI
>  
> +DEF("realtime", HAS_ARG, QEMU_OPTION_realtime,
> +    "-realtime [mlock=on|off]\n"
> +    "                run qemu with realtime features\n"
> +    "                mlock=on|off controls mlock support (default: on)\n",
> +    QEMU_ARCH_ALL)
> +STEXI
> +@item -realtime mlock=on|off
> +@findex -realtime
> +Run qemu with realtime features.
> +mlocking qemu and guest memory can be enabled via @option{mlock=on} 
> +(enabled by default).
> +ETEXI
> +
>  DEF("gdb", HAS_ARG, QEMU_OPTION_gdb, \
>      "-gdb dev        wait for gdb connection on 'dev'\n", QEMU_ARCH_ALL)
>  STEXI
> diff --git a/vl.c b/vl.c
> index 1355f69..c16c8ad 100644
> --- a/vl.c
> +++ b/vl.c
> @@ -491,6 +491,18 @@ static QemuOptsList qemu_object_opts = {
>      },
>  };
>  
> +static QemuOptsList qemu_realtime_opts = {
> +    .name = "realtime",
> +    .head = QTAILQ_HEAD_INITIALIZER(qemu_realtime_opts.head),
> +    .desc = {
> +        {
> +            .name = "mlock",
> +            .type = QEMU_OPT_BOOL,
> +        },
> +        { /* end of list */ }
> +    },
> +};
> +
>  const char *qemu_get_vm_name(void)
>  {
>      return qemu_name;
> @@ -1384,6 +1396,17 @@ static void smp_parse(const char *optarg)
>          max_cpus = smp_cpus;
>  }
>  
> +static void configure_realtime(QemuOpts *opts) {
> +    bool is_mlock;
> +
> +    is_mlock = qemu_opt_get_bool(opts, "mlock", true);
> +
> +    if (is_mlock) {
> +        os_mlock();
> +    }
> +}
> +
>  /***********************************************************/
>  /* USB devices */
>  
> @@ -2860,6 +2883,7 @@ int main(int argc, char **argv, char **envp)
>      qemu_add_opts(&qemu_sandbox_opts);
>      qemu_add_opts(&qemu_add_fd_opts);
>      qemu_add_opts(&qemu_object_opts);
> +    qemu_add_opts(&qemu_realtime_opts);
>  
>      runstate_init();
>  
> @@ -3806,6 +3830,13 @@ int main(int argc, char **argv, char **envp)
>                      exit(1);
>                  }
>                  break;
> +            case QEMU_OPTION_realtime:
> +                opts = qemu_opts_parse(qemu_find_opts("realtime"), optarg, 0);
> +                if (!opts) {
> +                    exit(1);
> +                }
> +                configure_realtime(opts);
> +                break;
>              default:
>                  os_parse_cmd_args(popt->index, optarg);
>              }
> 

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Re: [Dle-develop] [PATCH v9 2/3] trace, x86: add x86 irq vector tracepoints

[Seiji A. <sei...@hd...>]

OK. I will update my patch.

Seiji

> -----Original Message-----
> From: Steven Rostedt [mailto:ro...@go...]
> Sent: Tuesday, February 19, 2013 1:41 PM
> To: H. Peter Anvin
> Cc: Seiji Aguchi; x8...@ke...; lin...@vg...; Thomas Gleixner (tg...@li...); 'mi...@el...'
> (mi...@el...); Borislav Petkov (bp...@al...); Satoru Moriya; dle...@li...; lin...@vg...;
> Luck, Tony (ton...@in...)
> Subject: Re: [PATCH v9 2/3] trace,x86: add x86 irq vector tracepoints
> 
> On Mon, 2013-02-18 at 20:39 -0800, H. Peter Anvin wrote:
> 
> > > static void switch_to_trace_idt(void *arg) {
> > >      load_idt(&trace_idt_descr);
> > > }
> > >
> > > static void restore_original_idt(void *arg) {
> > >      load_idt(this_cpu_ptr(&idt_descr));
> > > }
> > >
> >
> > Yes.  If there needs to be handshaking about whose IDT is currently
> > installed I'm much happier if that handshake is done explicitly,
> > rather than as a save/restore function which will break when we have
> > to add another one which for whatever reason isn't nesting.
> 
> Agreed.
> 
> Seiji, can you make the update?
> 
> Thanks,
> 
> -- Steve
> 

Re: [Dle-develop] [PATCH v9 2/3] trace, x86: add x86 irq vector tracepoints

[Steven R. <ro...@go...>]

On Mon, 2013-02-18 at 20:39 -0800, H. Peter Anvin wrote:

> > static void switch_to_trace_idt(void *arg)
> > {
> >      load_idt(&trace_idt_descr);
> > }
> > 
> > static void restore_original_idt(void *arg)
> > {
> >      load_idt(this_cpu_ptr(&idt_descr));
> > }
> > 
> 
> Yes.  If there needs to be handshaking about whose IDT is currently
> installed I'm much happier if that handshake is done explicitly, rather
> than as a save/restore function which will break when we have to add
> another one which for whatever reason isn't nesting.

Agreed.

Seiji, can you make the update?

Thanks,

-- Steve

Re: [Dle-develop] [PATCH v9 2/3] trace, x86: add x86 irq vector tracepoints

[H. P. A. <hp...@zy...>]

On 02/18/2013 08:24 PM, Steven Rostedt wrote:
> On Mon, 2013-02-18 at 15:49 -0800, H. Peter Anvin wrote:
> 
>> What about the following:
>>
>>> The base address of the IDT doesn't generally change... the one
>>> exception is when we do the funny NMI workaround.
>>>
>>> For that reason, I would be happier if we just restored the standard
>>> value instead of saving/restoring stuff.
> 
> Basically what you are saying, is to have his code do what the NMI code
> originally did, but can't now, due to there being another IDT table
> (from Seiji's changes).
> 
> static void switch_to_trace_idt(void *arg)
> {
>      load_idt(&trace_idt_descr);
> }
> 
> static void restore_original_idt(void *arg)
> {
>      load_idt(this_cpu_ptr(&idt_descr));
> }
> 

Yes.  If there needs to be handshaking about whose IDT is currently
installed I'm much happier if that handshake is done explicitly, rather
than as a save/restore function which will break when we have to add
another one which for whatever reason isn't nesting.

	-hpa

Re: [Dle-develop] [PATCH v9 2/3] trace, x86: add x86 irq vector tracepoints

[Steven R. <ro...@go...>]

On Mon, 2013-02-18 at 15:49 -0800, H. Peter Anvin wrote:

> What about the following:
> 
> > The base address of the IDT doesn't generally change... the one
> > exception is when we do the funny NMI workaround.
> >
> > For that reason, I would be happier if we just restored the standard
> > value instead of saving/restoring stuff.

Basically what you are saying, is to have his code do what the NMI code
originally did, but can't now, due to there being another IDT table
(from Seiji's changes).

static void switch_to_trace_idt(void *arg)
{
     load_idt(&trace_idt_descr);
}

static void restore_original_idt(void *arg)
{
     load_idt(this_cpu_ptr(&idt_descr));
}

-- Steve

Re: [Dle-develop] [PATCH v9 2/3] trace, x86: add x86 irq vector tracepoints

[H. P. A. <hp...@zy...>]

On 02/18/2013 03:45 PM, Seiji Aguchi wrote:
>>> Not-yet-signed-off-by: Steven Rostedt <ro...@go...>
>>>
>>> ... so I was holding off on doing anything with it.
>>
>> Heh, and I was waiting for comments from you before doing anything further with it ;-)
>>
>> Email review deadlock!
>
> So, how do you plan to push ahead with this patch?
>
> https://lkml.org/lkml/2013/2/1/532
>
> <snip>
> I think I got all the cases, as NMIs causes the store/restore functions to be re-entrent without any locks.
> <snip>
>
> Steven,
> if you think you got all the cases, you can do more testing.
> What is your concern?
>
> I hope this patch will be included in 3.9.
>

What about the following:

> The base address of the IDT doesn't generally change... the one
> exception is when we do the funny NMI workaround.
>
> For that reason, I would be happier if we just restored the standard
> value instead of saving/restoring stuff.

	-hpa

-- 
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel.  I don't speak on their behalf.