Messages in this thread Patch in this message | | | From | Chengming Zhou <> | Subject | [PATCH] sched/cpuacct: fix percpu time accounting | Date | Wed, 8 Dec 2021 15:38:36 +0800 |
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The usage percpu data is the CPU time consumed on each CPU by all tasks in this cgroup (including tasks lower in the hierarchy). When cpuacct_charge called from other CPUs, we should use the CPU of task, not this CPU.
e.g. cpuacct_charge+1 update_curr+332 enqueue_entity+70 enqueue_task_fair+169 activate_task+57 attach_task+46 load_balance+1512 run_rebalance_domains+451 __do_softirq+282 sysvec_apic_timer_interrupt+159 asm_sysvec_apic_timer_interrupt+18 native_safe_halt+11 default_idle+10 default_enter_idle+45 cpuidle_enter_state+130 cpuidle_enter+47 do_idle+489 cpu_startup_entry+25 start_secondary+261 secondary_startup_64_no_verify+176
Reported-by: Xuan Lu <luxuan.windniw@bytedance.com> Reported-by: Minye Zhu <zhuminye@bytedance.com> Co-developed-by: Qiang Wang <wangqiang.wq.frank@bytedance.com> Signed-off-by: Qiang Wang <wangqiang.wq.frank@bytedance.com> Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com> --- kernel/sched/cpuacct.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/kernel/sched/cpuacct.c b/kernel/sched/cpuacct.c index 893eece65bfd..aab51c88bd34 100644 --- a/kernel/sched/cpuacct.c +++ b/kernel/sched/cpuacct.c @@ -341,6 +341,7 @@ void cpuacct_charge(struct task_struct *tsk, u64 cputime) struct cpuacct *ca; int index = CPUACCT_STAT_SYSTEM; struct pt_regs *regs = get_irq_regs() ? : task_pt_regs(tsk); + unsigned int cpu = task_cpu(tsk); if (regs && user_mode(regs)) index = CPUACCT_STAT_USER; @@ -348,7 +349,7 @@ void cpuacct_charge(struct task_struct *tsk, u64 cputime) rcu_read_lock(); for (ca = task_ca(tsk); ca; ca = parent_ca(ca)) - __this_cpu_add(ca->cpuusage->usages[index], cputime); + per_cpu_ptr(ca->cpuusage, cpu)->usages[index] += cputime; rcu_read_unlock(); } -- 2.11.0
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