From: Martin Schwidefsky <schwidefsky@de.ibm.com>
Date: Fri, 26 Oct 2012 15:17:44 +0000 (+0200)
Subject: sched/mm: call finish_arch_post_lock_switch in idle_task_exit and use_mm
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=a53efe5ff88d0283bae8a2c2fa066d0fff31dc91;p=linux-beck.git

sched/mm: call finish_arch_post_lock_switch in idle_task_exit and use_mm

The finish_arch_post_lock_switch is called at the end of the task
switch after all locks have been released. In concept it is paired
with the switch_mm function, but the current code only does the
call in finish_task_switch. Add the call to idle_task_exit and
use_mm. One use case for the additional calls is s390 which will
use finish_arch_post_lock_switch to wait for the completion of
TLB flush operations.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
---

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index b46131ef6aab..4b0739c9558e 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -4692,8 +4692,10 @@ void idle_task_exit(void)
 
 	BUG_ON(cpu_online(smp_processor_id()));
 
-	if (mm != &init_mm)
+	if (mm != &init_mm) {
 		switch_mm(mm, &init_mm, current);
+		finish_arch_post_lock_switch();
+	}
 	mmdrop(mm);
 }
 
diff --git a/mm/mmu_context.c b/mm/mmu_context.c
index 8a8cd0265e52..f802c2d216a7 100644
--- a/mm/mmu_context.c
+++ b/mm/mmu_context.c
@@ -31,6 +31,9 @@ void use_mm(struct mm_struct *mm)
 	tsk->mm = mm;
 	switch_mm(active_mm, mm, tsk);
 	task_unlock(tsk);
+#ifdef finish_arch_post_lock_switch
+	finish_arch_post_lock_switch();
+#endif
 
 	if (active_mm != mm)
 		mmdrop(active_mm);