* Daniel Walker <[EMAIL PROTECTED]> wrote:
> It looks like sched_class->enqueue_task() is NULL and that's why the
> system hangs ..
>
> The reason why that happens is because check_pgt_cache() is called
> from the idle thread, and with PREEMPT_RT check_pgt_cache() locks at
> least one mutex .. Once the idle thread is on a wait_list, as soon as
> it's woke by the mutex owner the system will crash in enqueue_task.
> Since the idle thread has a NULL sched_class->enqueue_task ..
>
> check_pgt_cache() is already getting called from the desched_thread()
> , so I think it could just be removed from i386 cpu_idle().
>
> Anyone have comments on the theory above?
yeah, that call definitely looks wrong in cpu_idle(). Most of the other
check_pgd_cache() calls introduced by commit f1d1a842 look wrong too in
an -rt context. Fix is below.
Ingo
Index: linux-rt.q/arch/i386/kernel/process.c
===================================================================
--- linux-rt.q.orig/arch/i386/kernel/process.c
+++ linux-rt.q/arch/i386/kernel/process.c
@@ -189,7 +189,6 @@ void cpu_idle(void)
tick_nohz_stop_sched_tick();
- check_pgt_cache();
rmb();
idle = pm_idle;
-
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