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| author |   Christian Borntraeger <borntraeger@de.ibm.com> | 2014-12-12 10:44:20 +0100 |
|---|---|---|
| committer |   Martin Schwidefsky <schwidefsky@de.ibm.com> | 2014-12-18 09:55:56 +0100 |
| commit | 032014bc04ae97fd0474f311259db7d669e47507 (patch) | |
| tree | 43e689bed5919bf7813eab3ff227e8675a885ce1 /arch/s390/kernel/vtime.c | |
| parent | s390/zcrypt: kernel oops at insmod of the z90crypt device driver (diff) | |
| download | linux-dev-032014bc04ae97fd0474f311259db7d669e47507.tar.xz linux-dev-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>
Diffstat (limited to 'arch/s390/kernel/vtime.c')
| -rw-r--r-- | arch/s390/kernel/vtime.c | 2 |
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; |