Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 5f40d804 authored by Li Zefan's avatar Li Zefan Committed by Ingo Molnar
Browse files

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: default avatarLi Zefan <lizefan@huawei.com>
Acked-by: default avatarPeter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/515536B7.6060602@huawei.com


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 543bc0e7

kernel/sched/cpuacct.c

+2 −2
Original line number Diff line number Diff line
@@ -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();

}

kernel/sched/cpuacct.h

+5 −0
Original line number Diff line number Diff line
@@ -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)