From: Chengming Zhou <zhouchengming@bytedance.com>
To: Suren Baghdasaryan <surenb@google.com>,
Johannes Weiner <hannes@cmpxchg.org>
Cc: quic_pkondeti@quicinc.com, peterz@infradead.org,
quic_charante@quicinc.com, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] sched/psi: Fix avgs_work re-arm in psi_avgs_work()
Date: Fri, 14 Oct 2022 10:03:58 +0800 [thread overview]
Message-ID: <7dba12ce-f981-6017-0613-542472e3ec5c@bytedance.com> (raw)
In-Reply-To: <CAJuCfpFo5EEEg24VLSmcPo=VDMszB9Q2a4L_Eq6E9VWnbsBJDQ@mail.gmail.com>
On 2022/10/14 00:10, Suren Baghdasaryan wrote:
> On Thu, Oct 13, 2022 at 8:52 AM Johannes Weiner <hannes@cmpxchg.org> wrote:
>>
>> On Thu, Oct 13, 2022 at 07:06:55PM +0800, Chengming Zhou wrote:
>>> Should I still need to copy groupc->tasks[] out for the current_cpu as you
>>> suggested before?
>>
>> It'd be my preference as well. This way the resched logic can be
>> consolidated into a single block of comment + code at the end of the
>> function.
>
> Sounds good to me. If we are copying times in the retry loop then
> let's move the `reschedule =` decision out of that loop completely. At
> the end of get_recent_times we can do:
>
> if (cpu == current_cpu)
> reschedule = tasks[NR_RUNNING] +
> tasks[NR_IOWAIT] +
> tasks[NR_MEMSTALL] > 1;
> else
> reschedule = *pchanged_states & (1 << PSI_NONIDLE);
>
Ok, I will send an updated patch later.
Thanks!
>
>>
>>> @@ -242,6 +242,8 @@ static void get_recent_times(struct psi_group *group, int cpu,
>>> u32 *pchanged_states)
>>> {
>>> struct psi_group_cpu *groupc = per_cpu_ptr(group->pcpu, cpu);
>>> + int current_cpu = raw_smp_processor_id();
>>> + bool reschedule;
>>> u64 now, state_start;
>>> enum psi_states s;
>>> unsigned int seq;
>>> @@ -256,6 +258,10 @@ static void get_recent_times(struct psi_group *group, int cpu,
>>> memcpy(times, groupc->times, sizeof(groupc->times));
>>> state_mask = groupc->state_mask;
>>> state_start = groupc->state_start;
>>> + if (cpu == current_cpu)
>>> + reschedule = groupc->tasks[NR_RUNNING] +
>>> + groupc->tasks[NR_IOWAIT] +
>>> + groupc->tasks[NR_MEMSTALL] > 1;
>>> } while (read_seqcount_retry(&groupc->seq, seq));
>>
>> This also matches psi_show() and the poll worker. They don't currently
>> use the flag, but it's somewhat fragile and confusing. Add a test for
>> current_work() == &group->avgs_work?
>
> Good point. (tasks[NR_RUNNING] + tasks[NR_IOWAIT] + tasks[NR_MEMSTALL]
>> 1) condition should also contain this check.
next prev parent reply other threads:[~2022-10-14 2:04 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-13 14:08 PSI idle-shutoff Pavan Kondeti
2022-09-15 6:20 ` Pavan Kondeti
2022-09-17 5:45 ` Suren Baghdasaryan
2022-10-03 6:11 ` Suren Baghdasaryan
2022-10-05 16:32 ` Suren Baghdasaryan
2022-10-09 12:41 ` Chengming Zhou
2022-10-09 13:17 ` Chengming Zhou
2022-10-10 6:18 ` Pavan Kondeti
2022-10-10 6:43 ` Pavan Kondeti
2022-10-10 6:57 ` [External] " Chengming Zhou
2022-10-10 8:30 ` Chengming Zhou
2022-10-10 9:09 ` Pavan Kondeti
2022-10-10 9:22 ` Chengming Zhou
2022-10-10 20:59 ` Suren Baghdasaryan
2022-10-10 20:33 ` Suren Baghdasaryan
2022-10-10 5:57 ` Pavan Kondeti
2022-10-10 9:01 ` Pavan Kondeti
2022-10-10 6:25 ` Pavan Kondeti
2022-10-10 10:42 ` [PATCH] sched/psi: Fix avgs_work re-arm in psi_avgs_work() Chengming Zhou
2022-10-10 21:21 ` Suren Baghdasaryan
2022-10-11 0:07 ` Chengming Zhou
2022-10-11 17:00 ` Suren Baghdasaryan
2022-10-12 2:10 ` Chengming Zhou
2022-10-12 18:24 ` Suren Baghdasaryan
2022-10-13 2:23 ` Chengming Zhou
2022-10-13 11:06 ` Chengming Zhou
2022-10-13 15:52 ` Johannes Weiner
2022-10-13 16:10 ` Suren Baghdasaryan
2022-10-14 2:03 ` Chengming Zhou [this message]
2022-10-14 2:02 ` Chengming Zhou
2022-10-28 6:42 ` [tip: sched/core] " tip-bot2 for Chengming Zhou
2022-10-28 6:50 ` [External] " Chengming Zhou
2022-10-28 15:58 ` Suren Baghdasaryan
2022-10-28 16:05 ` Chengming Zhou
2022-10-28 19:53 ` [External] " Peter Zijlstra
2022-10-29 11:55 ` Peter Zijlstra
2022-10-29 12:40 ` Chengming Zhou
2022-10-29 18:46 ` Suren Baghdasaryan
[not found] ` <20221010105710.171-1-hdanton@sina.com>
2022-10-10 21:16 ` PSI idle-shutoff Suren Baghdasaryan
[not found] ` <20221011113818.340-1-hdanton@sina.com>
2022-10-11 17:11 ` Suren Baghdasaryan
[not found] ` <20221012062034.486-1-hdanton@sina.com>
2022-10-12 15:40 ` Suren Baghdasaryan
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