Messages in this thread | | | Date | Fri, 22 Jul 2022 14:13:02 +0800 | Subject | Re: [PATCH 9/9] sched/psi: add PSI_IRQ to track IRQ/SOFTIRQ pressure | From | Chengming Zhou <> |
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On 2022/7/22 11:30, Abel Wu wrote: > Hi Chengming, > > On 7/21/22 12:04 PM, Chengming Zhou Wrote: >> Now PSI already tracked workload pressure stall information for >> CPU, memory and IO. Apart from these, IRQ/SOFTIRQ could have >> obvious impact on some workload productivity, such as web service >> workload. >> >> When CONFIG_IRQ_TIME_ACCOUNTING, we can get IRQ/SOFTIRQ delta time >> from update_rq_clock_task(), in which we can record that delta >> to CPU curr task's cgroups as PSI_IRQ_FULL status. > > The {soft,}irq affection should be equal to all the runnable tasks > on that cpu, not only rq->curr. Further I think irqstall is per-cpu > rather than per-cgroup.
Although IRQ/SOFTIRQ is per-cpu, it's the rq->curr who own the CPU at the time and pay for it, meanwhile other groups would be thought as PSI_CPU_FULL.
So I think it's reasonable to account this IRQ/SOFTIRQ delta to rq->curr's groups as PSI_IRQ_FULL pressure stall. And per-cpu IRQ stall can also get from psi_system.
Thanks.
> > Abel
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