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| author | Chengming Zhou <zhouchengming@bytedance.com> | 2022-02-20 08:14:25 +0300 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2022-03-01 18:18:38 +0300 |
| commit | dc6e0818bc9a0336d9accf3ea35d146d72aa7a18 (patch) | |
| tree | 81effaa3f69fa5c07bc23c9c0fb7899d149732af /kernel/sched | |
| parent | 248cc9993d1cc12b8e9ed716cc3fc09f6c3517dd (diff) | |
| download | linux-dc6e0818bc9a0336d9accf3ea35d146d72aa7a18.tar.xz | |
sched/cpuacct: Optimize away RCU read lock
Since cpuacct_charge() is called from the scheduler update_curr(),
we must already have rq lock held, then the RCU read lock can
be optimized away.
And do the same thing in it's wrapper cgroup_account_cputime(),
but we can't use lockdep_assert_rq_held() there, which defined
in kernel/sched/sched.h.
Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220220051426.5274-2-zhouchengming@bytedance.com
Diffstat (limited to 'kernel/sched')
| -rw-r--r-- | kernel/sched/cpuacct.c | 4 |
1 files changed, 1 insertions, 3 deletions
diff --git a/kernel/sched/cpuacct.c b/kernel/sched/cpuacct.c index 307800586ac8..f79f88456d72 100644 --- a/kernel/sched/cpuacct.c +++ b/kernel/sched/cpuacct.c @@ -337,12 +337,10 @@ void cpuacct_charge(struct task_struct *tsk, u64 cputime) unsigned int cpu = task_cpu(tsk); struct cpuacct *ca; - rcu_read_lock(); + lockdep_assert_rq_held(cpu_rq(cpu)); for (ca = task_ca(tsk); ca; ca = parent_ca(ca)) *per_cpu_ptr(ca->cpuusage, cpu) += cputime; - - rcu_read_unlock(); } /* |