Messages in this thread | | | Subject | Re: [PATCH] sched/fair: Optimize select_idle_cpu | From | "chengjian (D)" <> | Date | Fri, 13 Dec 2019 09:51:30 +0800 |
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On 2019/12/12 23:04, Peter Zijlstra wrote: > On Thu, Dec 12, 2019 at 10:41:02PM +0800, Cheng Jian wrote: >> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c >> index 08a233e97a01..16a29b570803 100644 >> --- a/kernel/sched/fair.c >> +++ b/kernel/sched/fair.c >> @@ -5834,6 +5834,7 @@ static int select_idle_cpu(struct task_struct *p, struct sched_domain *sd, int t >> s64 delta; >> int this = smp_processor_id(); >> int cpu, nr = INT_MAX, si_cpu = -1; >> + struct cpumask cpus; > NAK, you must not put a cpumask on stack. > > .
Hi, Peter
I saw the same work in select_idle_core, and I was wondering why the per_cpu variable was
needed for this yesterday. Now I think I probably understand : cpumask may be too large,
putting it on the stack may cause overflow. Is this correct ?
I'm sorry I made a mistake like this. I will fix it in v2
Thank you very much.
-- Cheng Jian
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