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authorChristian Borntraeger <borntraeger@de.ibm.com>2014-12-12 10:44:20 +0100
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2014-12-18 09:55:56 +0100
commit032014bc04ae97fd0474f311259db7d669e47507 (patch)
tree43e689bed5919bf7813eab3ff227e8675a885ce1
parents390/zcrypt: kernel oops at insmod of the z90crypt device driver (diff)
downloadlinux-032014bc04ae97fd0474f311259db7d669e47507.tar.xz
linux-032014bc04ae97fd0474f311259db7d669e47507.zip
s390/vtime: Get rid of redundant WARN_ON
in the cpu time accounting function vtime_account_irq_enter (vtime_account_system) we use a WARN_ON_ONCE(!irqs_disabled()). This is redundant as the function virt_timer_forward is always called and has a BUG_ON(!irqs_disabled()). This saves several nanoseconds in my specific testcase (KVM entry/exit) and probably all other callers like (soft)irq entry/exit. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
-rw-r--r--arch/s390/kernel/vtime.c2
1 files changed, 0 insertions, 2 deletions
diff --git a/arch/s390/kernel/vtime.c b/arch/s390/kernel/vtime.c
index 7f0089d9a4aa..e34122e539a1 100644
--- a/arch/s390/kernel/vtime.c
+++ b/arch/s390/kernel/vtime.c
@@ -128,8 +128,6 @@ void vtime_account_irq_enter(struct task_struct *tsk)
struct thread_info *ti = task_thread_info(tsk);
u64 timer, system;
- WARN_ON_ONCE(!irqs_disabled());
-
timer = S390_lowcore.last_update_timer;
S390_lowcore.last_update_timer = get_vtimer();
S390_lowcore.system_timer += timer - S390_lowcore.last_update_timer;