Re: scheduler: IRQs disabled over context switches

From: Ingo Molnar
Date: Mon May 24 2004 - 02:17:14 EST



* Nick Piggin <nickpiggin@xxxxxxxxxxxx> wrote:

> >+# define prepare_arch_switch(rq, next) \
> >+ do { \
> >+ spin_lock(&(next)->switch_lock); \
> >+ spin_unlock(&(rq)->lock); \
>
> spin_unlock_irq?

and spin_unlock in the finish_arch_switch() case, instead of
spin_unlock_irq. New patch below.

Ingo

--- linux/kernel/sched.c.orig
+++ linux/kernel/sched.c
@@ -247,9 +247,15 @@ static DEFINE_PER_CPU(struct runqueue, r
* Default context-switch locking:
*/
#ifndef prepare_arch_switch
-# define prepare_arch_switch(rq, next) do { } while (0)
-# define finish_arch_switch(rq, next) spin_unlock_irq(&(rq)->lock)
-# define task_running(rq, p) ((rq)->curr == (p))
+# define prepare_arch_switch(rq, next) \
+ do { \
+ spin_lock(&(next)->switch_lock); \
+ spin_unlock_irq(&(rq)->lock); \
+ } while (0)
+# define finish_arch_switch(rq, prev) \
+ spin_unlock(&(prev)->switch_lock)
+# define task_running(rq, p) \
+ ((rq)->curr == (p) || spin_is_locked(&(p)->switch_lock))
#endif

/*
-
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