Update of /cvsroot/linuxconsole/ruby/linux/kernel
In directory usw-pr-cvs1:/tmp/cvs-serv12464
Modified Files:
printk.c
Log Message:
Fixed a spinlock issue which I believe was locking SMP machines.
Index: printk.c
===================================================================
RCS file: /cvsroot/linuxconsole/ruby/linux/kernel/printk.c,v
retrieving revision 1.18
retrieving revision 1.19
diff -u -d -r1.18 -r1.19
--- printk.c 2001/12/06 23:32:51 1.18
+++ printk.c 2001/12/07 00:00:08 1.19
@@ -448,6 +448,7 @@
* We own the drivers list. We can drop the lock and
* let release_console_sem() print the text
*/
+ spin_unlock(&console_lock);
if ((con->flags & CON_ENABLED) && con->write) {
driver = get_tty_driver(con->device(con));
if (driver && !down_trylock(&driver->tty_lock)) {
@@ -455,6 +456,7 @@
release_console_sem(con->device(con));
}
}
+ spin_lock(&console_lock);
}
spin_unlock(&console_lock);
return printed_len;
@@ -475,8 +477,11 @@
if (in_interrupt())
BUG();
- down(&driver->tty_lock);
- driver->may_schedule = 1;
+
+ if (driver) {
+ down(&driver->tty_lock);
+ driver->may_schedule = 1;
+ }
}
EXPORT_SYMBOL(acquire_console_sem);
@@ -502,15 +507,15 @@
unsigned long flags;
struct console *con;
- if (driver->flags & TTY_DRIVER_CONSOLE) {
- spin_lock(&console_lock);
- /* Look for new messages */
- for (con = console_drivers; con; con = con->next) {
- if (con->device(con) == device)
- break;
- }
- spin_unlock(&console_lock);
+ spin_lock(&console_lock);
+ /* Look for new messages */
+ for (con = console_drivers; con; con = con->next) {
+ if (con->device(con) == device)
+ break;
+ }
+ spin_unlock(&console_lock);
+ if (con) {
for ( ; ; ) {
spin_lock_irqsave(&logbuf_lock, flags);
must_wake_klogd |= log_start - log_end;
@@ -526,8 +531,10 @@
if (must_wake_klogd && !oops_in_progress)
wake_up_interruptible(&log_wait);
}
- driver->may_schedule = 0;
- up(&driver->tty_lock);
+ if (driver) {
+ driver->may_schedule = 0;
+ up(&driver->tty_lock);
+ }
}
/** console_conditional_schedule - yield the CPU if required
@@ -638,12 +645,10 @@
int unregister_console(struct console * console)
{
- struct tty_driver *driver = get_tty_driver(console->device(console));
struct console *a,*b;
int res = 1;
- if (driver)
- release_console_sem(console->device(console));
+ release_console_sem(console->device(console));
spin_lock(&console_lock);
if (console_drivers == console) {
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