From: Wanpeng Li <kernellwp@gmail.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Ross Zwisler <zwisler@gmail.com>, Mike Galbraith <efault@gmx.de>,
Sachin Sant <sachinp@linux.vnet.ibm.com>,
Matt Fleming <matt@codeblueprint.co.uk>,
Michael Ellerman <mpe@ellerman.id.au>,
"linuxppc-dev@lists.ozlabs.org" <linuxppc-dev@lists.ozlabs.org>,
"linux-next@vger.kernel.org" <linux-next@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: [tip:sched/core] sched/core: Add debugging code to catch missing update_rq_clock() calls
Date: Wed, 22 Feb 2017 17:03:05 +0800 [thread overview]
Message-ID: <CANRm+CzSpr0psdn-ZoMV+S-Bq9s+JRADnnzT81ofwzNnkTqFVQ@mail.gmail.com> (raw)
In-Reply-To: <20170202155506.GX6515@twins.programming.kicks-ass.net>
2017-02-02 23:55 GMT+08:00 Peter Zijlstra <peterz@infradead.org>:
> On Tue, Jan 31, 2017 at 10:22:47AM -0700, Ross Zwisler wrote:
>> On Tue, Jan 31, 2017 at 4:48 AM, Mike Galbraith <efault@gmx.de> wrote:
>> > On Tue, 2017-01-31 at 16:30 +0530, Sachin Sant wrote:
>
>
> Could some of you test this? It seems to cure things in my (very)
> limited testing.
>
Tested-by: Wanpeng Li <wanpeng.li@hotmail.com>
> ---
> diff --git a/kernel/sched/core.c b/kernel/sched/core.c
> index 96e4ccc..b773821 100644
> --- a/kernel/sched/core.c
> +++ b/kernel/sched/core.c
> @@ -5609,7 +5609,7 @@ static void migrate_tasks(struct rq *dead_rq)
> {
> struct rq *rq = dead_rq;
> struct task_struct *next, *stop = rq->stop;
> - struct rq_flags rf, old_rf;
> + struct rq_flags rf;
> int dest_cpu;
>
> /*
> @@ -5628,7 +5628,9 @@ static void migrate_tasks(struct rq *dead_rq)
> * class method both need to have an up-to-date
> * value of rq->clock[_task]
> */
> + rq_pin_lock(rq, &rf);
> update_rq_clock(rq);
> + rq_unpin_lock(rq, &rf);
>
> for (;;) {
> /*
> @@ -5641,7 +5643,7 @@ static void migrate_tasks(struct rq *dead_rq)
> /*
> * pick_next_task assumes pinned rq->lock.
> */
> - rq_pin_lock(rq, &rf);
> + rq_repin_lock(rq, &rf);
> next = pick_next_task(rq, &fake_task, &rf);
> BUG_ON(!next);
> next->sched_class->put_prev_task(rq, next);
> @@ -5670,13 +5672,6 @@ static void migrate_tasks(struct rq *dead_rq)
> continue;
> }
>
> - /*
> - * __migrate_task() may return with a different
> - * rq->lock held and a new cookie in 'rf', but we need
> - * to preserve rf::clock_update_flags for 'dead_rq'.
> - */
> - old_rf = rf;
> -
> /* Find suitable destination for @next, with force if needed. */
> dest_cpu = select_fallback_rq(dead_rq->cpu, next);
>
> @@ -5685,7 +5680,6 @@ static void migrate_tasks(struct rq *dead_rq)
> raw_spin_unlock(&rq->lock);
> rq = dead_rq;
> raw_spin_lock(&rq->lock);
> - rf = old_rf;
> }
> raw_spin_unlock(&next->pi_lock);
> }
next prev parent reply other threads:[~2017-02-22 9:03 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-21 13:38 [PATCH v2 0/7] sched: Diagnostic checks for missing rq clock updates Matt Fleming
2016-09-21 13:38 ` [PATCH v2 1/7] sched/fair: Update the rq clock before detaching tasks Matt Fleming
2016-10-03 12:49 ` Peter Zijlstra
2016-10-03 14:37 ` Matt Fleming
2016-10-03 14:42 ` Peter Zijlstra
2016-09-21 13:38 ` [PATCH v2 2/7] sched/fair: Update rq clock before waking up new task Matt Fleming
2016-09-21 13:38 ` [PATCH v2 3/7] sched/fair: Update rq clock in task_hot() Matt Fleming
2016-09-21 13:38 ` [PATCH v2 4/7] sched: Add wrappers for lockdep_(un)pin_lock() Matt Fleming
2017-01-14 12:40 ` [tip:sched/core] sched/core: " tip-bot for Matt Fleming
2016-09-21 13:38 ` [PATCH v2 5/7] sched/core: Reset RQCF_ACT_SKIP before unpinning rq->lock Matt Fleming
2017-01-14 12:41 ` [tip:sched/core] " tip-bot for Matt Fleming
2016-09-21 13:38 ` [PATCH v2 6/7] sched/fair: Push rq lock pin/unpin into idle_balance() Matt Fleming
2017-01-14 12:41 ` [tip:sched/core] " tip-bot for Matt Fleming
2016-09-21 13:38 ` [PATCH v2 7/7] sched/core: Add debug code to catch missing update_rq_clock() Matt Fleming
2016-09-21 15:58 ` Petr Mladek
2016-09-21 19:08 ` Matt Fleming
2016-09-21 19:46 ` Thomas Gleixner
2016-09-22 0:44 ` Sergey Senozhatsky
2016-09-22 8:04 ` Peter Zijlstra
2016-09-22 8:36 ` Jan Kara
2016-09-22 9:39 ` Peter Zijlstra
2016-09-22 10:17 ` Peter Zijlstra
2017-01-14 12:44 ` [tip:sched/core] sched/core: Add debugging code to catch missing update_rq_clock() calls tip-bot for Matt Fleming
[not found] ` <87tw8gutp6.fsf@concordia.ellerman.id.au>
2017-01-30 21:34 ` Matt Fleming
2017-01-31 8:35 ` Michael Ellerman
2017-01-31 11:00 ` Sachin Sant
2017-01-31 11:48 ` Mike Galbraith
2017-01-31 17:22 ` Ross Zwisler
2017-02-02 15:55 ` Peter Zijlstra
2017-02-02 22:01 ` Matt Fleming
2017-02-03 3:05 ` Mike Galbraith
2017-02-03 4:33 ` Sachin Sant
2017-02-03 8:53 ` Peter Zijlstra
2017-02-03 12:59 ` Mike Galbraith
2017-02-03 13:37 ` Peter Zijlstra
2017-02-03 13:52 ` Mike Galbraith
2017-02-03 15:44 ` Paul E. McKenney
2017-02-03 15:54 ` Paul E. McKenney
2017-02-06 6:23 ` Sachin Sant
2017-02-06 15:10 ` Paul E. McKenney
2017-02-06 15:14 ` Paul E. McKenney
2017-02-03 13:04 ` Borislav Petkov
2017-02-22 9:03 ` Wanpeng Li [this message]
2017-02-24 9:16 ` [tip:sched/urgent] sched/core: Fix update_rq_clock() splat on hotplug (and suspend/resume) tip-bot for Peter Zijlstra
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