From: Wanpeng Li <kernellwp@gmail.com>
To: Mike Galbraith <umgwanakikbuti@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Pavan Kondeti <pkondeti@codeaurora.org>,
Ben Segall <bsegall@google.com>,
Matt Fleming <matt@codeblueprint.co.uk>,
Morten Rasmussen <morten.rasmussen@arm.com>,
Paul Turner <pjt@google.com>,
Thomas Gleixner <tglx@linutronix.de>,
Byungchul Park <byungchul.park@lge.com>,
Andrew Hunter <ahh@google.com>
Subject: Re: [patch] sched/fair: Move se->vruntime normalization state into struct sched_entity
Date: Mon, 23 May 2016 18:13:28 +0800 [thread overview]
Message-ID: <CANRm+CyO6SRn5vXv=ENi7V54RD9mWv_1_W5WAs9SGPcWWFk+Jg@mail.gmail.com> (raw)
In-Reply-To: <1463996435.4537.97.camel@gmail.com>
2016-05-23 17:40 GMT+08:00 Mike Galbraith <umgwanakikbuti@gmail.com>:
> On Mon, 2016-05-23 at 11:19 +0200, Peter Zijlstra wrote:
>> On Sun, May 22, 2016 at 09:00:01AM +0200, Mike Galbraith wrote:
>> > On Sat, 2016-05-21 at 21:00 +0200, Mike Galbraith wrote:
>> > > On Sat, 2016-05-21 at 16:04 +0200, Mike Galbraith wrote:
>> > >
>> > > > Wakees that were not migrated/normalized eat an unwanted min_vruntime,
>> > > > and likely take a size XXL latency hit. Big box running master bled
>> > > > profusely under heavy load until I turned TTWU_QUEUE off.
>> >
>> > May as well make it official and against master.today. Fly or die
>> > little patchlet.
>> >
>> > sched/fair: Move se->vruntime normalization state into struct sched_entity
>>
>> Does this work?
>
> Yup, bugs--. Kinda funny, I considered ~this way first, but thought
> you'd not that approach.. dang, got it back-assward ;-)
>
Nicer this one.
Reviewed-by: Wanpeng Li <wanpeng.li@hotmail.com>
>> ---
>> include/linux/sched.h | 1 +
>> kernel/sched/core.c | 18 +++++++++++-------
>> 2 files changed, 12 insertions(+), 7 deletions(-)
>>
>> diff --git a/include/linux/sched.h b/include/linux/sched.h
>> index 1b43b45a22b9..a2001e01b3df 100644
>> --- a/include/linux/sched.h
>> +++ b/include/linux/sched.h
>> @@ -1534,6 +1534,7 @@ struct task_struct {
>> unsigned sched_reset_on_fork:1;
>> unsigned sched_contributes_to_load:1;
>> unsigned sched_migrated:1;
>> + unsigned sched_remote_wakeup:1;
>> unsigned :0; /* force alignment to the next boundary */
>>
>> /* unserialized, strictly 'current' */
>> diff --git a/kernel/sched/core.c b/kernel/sched/core.c
>> index 404c0784b1fc..7f2cae4620c7 100644
>> --- a/kernel/sched/core.c
>> +++ b/kernel/sched/core.c
>> @@ -1768,13 +1768,15 @@ void sched_ttwu_pending(void)
>> cookie = lockdep_pin_lock(&rq->lock);
>>
>> while (llist) {
>> + int wake_flags = 0;
>> +
>> p = llist_entry(llist, struct task_struct,
>> wake_entry);
>> llist = llist_next(llist);
>> - /*
>> - * See ttwu_queue(); we only call
>> ttwu_queue_remote() when
>> - * its a x-cpu wakeup.
>> - */
>> - ttwu_do_activate(rq, p, WF_MIGRATED, cookie);
>> +
>> + if (p->sched_remote_wakeup)
>> + wake_flags = WF_MIGRATED;
>> +
>> + ttwu_do_activate(rq, p, wake_flags, cookie);
>> }
>>
>> lockdep_unpin_lock(&rq->lock, cookie);
>> @@ -1819,10 +1821,12 @@ void scheduler_ipi(void)
>> irq_exit();
>> }
>>
>> -static void ttwu_queue_remote(struct task_struct *p, int cpu)
>> +static void ttwu_queue_remote(struct task_struct *p, int cpu, int
>> wake_flags)
>> {
>> struct rq *rq = cpu_rq(cpu);
>>
>> + p->sched_remote_wakeup = !!(wake_flags & WF_MIGRATED);
>> +
>> if (llist_add(&p->wake_entry, &cpu_rq(cpu)->wake_list)) {
>> if (!set_nr_if_polling(rq->idle))
>> smp_send_reschedule(cpu);
>> @@ -1869,7 +1873,7 @@ static void ttwu_queue(struct task_struct *p,
>> int cpu, int wake_flags)
>> #if defined(CONFIG_SMP)
>> if (sched_feat(TTWU_QUEUE) &&
>> !cpus_share_cache(smp_processor_id(), cpu)) {
>> sched_clock_cpu(cpu); /* sync clocks x-cpu */
>> - ttwu_queue_remote(p, cpu);
>> + ttwu_queue_remote(p, cpu, wake_flags);
>> return;
>> }
>> #endif
--
Regards,
Wanpeng Li
next prev parent reply other threads:[~2016-05-23 10:13 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-10 17:43 [PATCH 0/3] sched: Fix wakeup preemption regression Peter Zijlstra
2016-05-10 17:43 ` [PATCH 1/3] sched,fair: Move record_wakee() Peter Zijlstra
2016-05-12 10:27 ` Matt Fleming
2016-05-12 10:31 ` Peter Zijlstra
2016-05-10 17:43 ` [PATCH 2/3] sched,fair: Fix local starvation Peter Zijlstra
2016-05-10 20:21 ` Ingo Molnar
2016-05-10 22:23 ` Peter Zijlstra
2016-05-20 21:24 ` Matt Fleming
2016-05-21 14:04 ` Mike Galbraith
2016-05-21 19:00 ` Mike Galbraith
2016-05-22 7:00 ` [patch] sched/fair: Move se->vruntime normalization state into struct sched_entity Mike Galbraith
2016-05-22 9:36 ` Peter Zijlstra
2016-05-22 9:52 ` Mike Galbraith
2016-05-22 10:33 ` Peter Zijlstra
2016-05-23 9:19 ` Peter Zijlstra
2016-05-23 9:40 ` Mike Galbraith
2016-05-23 10:13 ` Wanpeng Li [this message]
2016-05-23 10:26 ` Mike Galbraith
2016-05-23 12:28 ` Peter Zijlstra
2016-05-25 7:12 ` [tip:sched/urgent] sched/core: Fix remote wakeups tip-bot for Peter Zijlstra
2016-05-22 6:50 ` [PATCH 2/3] sched,fair: Fix local starvation Wanpeng Li
2016-05-22 7:15 ` Mike Galbraith
2016-05-22 7:27 ` Wanpeng Li
2016-05-22 7:32 ` Mike Galbraith
2016-05-22 7:42 ` Wanpeng Li
2016-05-22 8:04 ` Mike Galbraith
2016-05-22 8:24 ` Wanpeng Li
2016-05-22 8:39 ` Mike Galbraith
2016-05-22 8:50 ` Wanpeng Li
2016-05-10 17:43 ` [PATCH 3/3] sched: Kill sched_class::task_waking Peter Zijlstra
2016-05-11 5:55 ` [PATCH 0/3] sched: Fix wakeup preemption regression Mike Galbraith
2016-05-12 9:56 ` Pavan Kondeti
2016-05-12 10:52 ` Matt Fleming
2016-05-24 17:04 [patch] sched/fair: Move se->vruntime normalization state into struct sched_entity Paul E. McKenney
2016-05-25 17:49 ` Paul E. McKenney
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