From: Mike Galbraith <umgwanakikbuti@gmail.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: mingo@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@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 11:40:35 +0200 [thread overview]
Message-ID: <1463996435.4537.97.camel@gmail.com> (raw)
In-Reply-To: <20160523091907.GD15728@worktop.ger.corp.intel.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 ;-)
> ---
> 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
next prev parent reply other threads:[~2016-05-23 9:40 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 [this message]
2016-05-23 10:13 ` Wanpeng Li
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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