Commit-ID: 5f40d804325e925409907e29f46ecb012090b6c2 Gitweb: http://git.kernel.org/tip/5f40d804325e925409907e29f46ecb012090b6c2 Author: Li Zefan <[email protected]> AuthorDate: Fri, 29 Mar 2013 14:37:43 +0800 Committer: Ingo Molnar <[email protected]> CommitDate: Wed, 10 Apr 2013 13:54:18 +0200
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 <[email protected]> Acked-by: Peter Zijlstra <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]> --- kernel/sched/cpuacct.c | 4 ++-- 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 b2aaaba..071ae8d 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 45c1682..b2f79ad1 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) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
