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| author | Li Zefan <lizefan@huawei.com> | 2013-03-29 14:37:43 +0800 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2013-04-10 13:54:18 +0200 |
| commit | 5f40d804325e925409907e29f46ecb012090b6c2 (patch) | |
| tree | 28cd9dd3f0a7ed059d1167ba8c77e725445e9986 /kernel/sched | |
| parent | 543bc0e76e6bb84300eaf9833edc5a481f788678 (diff) | |
| download | linux-5f40d804325e925409907e29f46ecb012090b6c2.tar.gz linux-5f40d804325e925409907e29f46ecb012090b6c2.tar.bz2 linux-5f40d804325e925409907e29f46ecb012090b6c2.zip | |
sched/cpuacct: Remove redundant NULL checks in cpuacct_acount_field()
This is a micro optimazation for a hot path.
- We don't need to check if @ca returned from task_ca() is NULL.
- We don't need to check if @ca returned from parent_ca() is NULL.
Signed-off-by: Li Zefan <lizefan@huawei.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/515536B7.6060602@huawei.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/sched')
| -rw-r--r-- | kernel/sched/cpuacct.c | 4 | ||||
| -rw-r--r-- | kernel/sched/cpuacct.h | 5 |
2 files changed, 7 insertions, 2 deletions
diff --git a/kernel/sched/cpuacct.c b/kernel/sched/cpuacct.c index b2aaaba16d46..071ae8d08181 100644 --- a/kernel/sched/cpuacct.c +++ b/kernel/sched/cpuacct.c @@ -237,10 +237,10 @@ void cpuacct_account_field(struct task_struct *p, int index, u64 val) rcu_read_lock(); ca = task_ca(p); - while (ca && (ca != &root_cpuacct)) { + while (ca != &root_cpuacct) { kcpustat = this_cpu_ptr(ca->cpustat); kcpustat->cpustat[index] += val; - ca = parent_ca(ca); + ca = __parent_ca(ca); } rcu_read_unlock(); } diff --git a/kernel/sched/cpuacct.h b/kernel/sched/cpuacct.h index 45c168207fcc..b2f79ad1e524 100644 --- a/kernel/sched/cpuacct.h +++ b/kernel/sched/cpuacct.h @@ -34,6 +34,11 @@ static inline struct cpuacct *task_ca(struct task_struct *tsk) struct cpuacct, css); } +static inline struct cpuacct *__parent_ca(struct cpuacct *ca) +{ + return cgroup_ca(ca->css.cgroup->parent); +} + static inline struct cpuacct *parent_ca(struct cpuacct *ca) { if (!ca->css.cgroup->parent) |