Re: [Kgdb-bugreport] [PATCH 05/37] kdb: core for kgdb back end

[Jason W. <jas...@wi...>]

Peter Zijlstra wrote:
> On Mon, 2009-12-28 at 10:33 -0600, Jason Wessel wrote:
>>  The reason we need the attached patch is to be able to call
>> curr_task() for kdb to perform some basic per cpu task analysis while
>> the system is stopped.
> 
> Right, so this set_curr_task() thing is way scary, maybe we can simplify
> things to only expose curr_task()?


I am not sure what you had in mind for a simplification.  Is it simply to only expose the function to kdb that we use, as follows in the patch below, or something else?

There are no calls to set_curr_task() from kdb.  The curr_task() was only needed because there was no way to get at cpu_curr() outside of kernel/sched.c.  I had just assumed curr_task() was the "official" helper function.

Jason.

diff --git a/kernel/sched.c b/kernel/sched.c
index c535cc4..76fa8e1 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -9784,9 +9784,9 @@ void normalize_rt_tasks(void)
 
 #endif /* CONFIG_MAGIC_SYSRQ */
 
-#ifdef CONFIG_IA64
+#if defined(CONFIG_IA64) || defined(CONFIG_KGDB_KDB)
 /*
- * These functions are only useful for the IA64 MCA handling.
+ * These functions are only useful for the IA64 MCA handling, or kdb.
  *
  * They can only be called when the whole system has been
  * stopped - every CPU needs to be quiescent, and no scheduling
@@ -9806,6 +9806,9 @@ struct task_struct *curr_task(int cpu)
 	return cpu_curr(cpu);
 }
 
+#endif /* defined(CONFIG_IA64) || defined(CONFIG_KGDB_KDB) */
+
+#ifdef CONFIG_IA64
 /**
  * set_curr_task - set the current task for a given cpu.
  * @cpu: the processor in question.