From: Ben Hutchings <ben@decadent.org.uk>
To: Mike Galbraith <umgwanakikbuti@gmail.com>,
Byungchul Park <byungchul.park@lge.com>,
Greg KH <gregkh@linuxfoundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>,
stable@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [STABLE] kernel oops which can be fixed by peterz's patches
Date: Tue, 23 Feb 2016 21:06:53 +0000 [thread overview]
Message-ID: <1456261613.9099.0.camel@decadent.org.uk> (raw)
In-Reply-To: <1455678179.3531.15.camel@gmail.com>
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On Wed, 2016-02-17 at 04:02 +0100, Mike Galbraith wrote:
[...]
@stable: Kernels that predate SCHED_DEADLINE can use this simple (and tested)
check in lieu of backport of the full 18 patch mainline treatment.
Signed-off-by: Mike Galbraith <umgwanakikbuti@gmail.com>
---
kernel/sched/fair.c | 9 +++++++++
1 file changed, 9 insertions(+)
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -4008,6 +4008,7 @@ int can_migrate_task(struct task_struct
* 2) cannot be migrated to this CPU due to cpus_allowed, or
* 3) running (obviously), or
* 4) are cache-hot on their current CPU.
+ * 5) p->pi_lock is held.
*/
if (throttled_lb_pair(task_group(p), env->src_cpu, env->dst_cpu))
return 0;
@@ -4049,6 +4050,14 @@ int can_migrate_task(struct task_struct
}
/*
+ * rt -> fair class change may be in progress. If we sneak in should
+ * double_lock_balance() release rq->lock, and move the task, we will
+ * cause switched_to_fair() to meet a passed but no longer valid rq.
+ */
+ if (raw_spin_is_locked(&p->pi_lock))
+ return 0;
+
+ /*
* Aggressive migration if:
* 1) task is cache cold, or
* 2) too many balance attempts have failed.
Queued up for 3.2, thanks.
Ben.
--
Ben Hutchings
Any smoothly functioning technology is indistinguishable from a rigged demo.
--
Ben Hutchings
Any smoothly functioning technology is indistinguishable from a rigged demo.
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next prev parent reply other threads:[~2016-02-23 21:07 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-01-05 8:52 [STABLE] kernel oops which can be fixed by peterz's patches Byungchul Park
2016-01-05 9:14 ` Peter Zijlstra
2016-01-12 8:47 ` Byungchul Park
2016-01-12 10:21 ` Willy Tarreau
2016-01-25 7:25 ` Byungchul Park
2016-02-16 7:08 ` Byungchul Park
2016-02-16 8:44 ` Peter Zijlstra
2016-02-16 17:42 ` Greg KH
2016-02-17 0:11 ` Byungchul Park
2016-02-17 0:41 ` Greg KH
2016-02-17 2:00 ` Byungchul Park
2016-02-17 3:01 ` Greg KH
2016-02-17 3:02 ` Mike Galbraith
2016-02-23 21:05 ` Ben Hutchings
2016-02-23 21:06 ` Ben Hutchings [this message]
2016-01-05 9:16 ` [PATCH for v3.14.58 1/7] sched: Clean up idle task SMP logic Byungchul Park
2016-01-05 9:16 ` [PATCH for v3.14.58 2/7] sched: Replace post_schedule with a balance callback list Byungchul Park
2016-01-05 9:16 ` [PATCH for v3.14.58 3/7] sched: Allow balance callbacks for check_class_changed() Byungchul Park
2016-01-05 9:16 ` [PATCH for v3.14.58 4/7] sched,rt: Remove return value from pull_rt_task() Byungchul Park
2016-01-05 9:16 ` [PATCH for v3.14.58 5/7] sched, rt: Convert switched_{from, to}_rt() / prio_changed_rt() to balance callbacks Byungchul Park
2016-01-05 9:16 ` [PATCH for v3.14.58 6/7] sched,dl: Remove return value from pull_dl_task() Byungchul Park
2016-01-05 9:16 ` [PATCH for v3.14.58 7/7] sched, dl: Convert switched_{from, to}_dl() / prio_changed_dl() to balance callbacks Byungchul Park
2016-01-05 9:24 ` [PATCH for v3.18.25 1/6] sched: Replace post_schedule with a balance callback list Byungchul Park
2016-01-05 9:24 ` [PATCH for v3.18.25 2/6] sched: Allow balance callbacks for check_class_changed() Byungchul Park
2016-01-05 9:24 ` [PATCH for v3.18.25 3/6] sched,rt: Remove return value from pull_rt_task() Byungchul Park
2016-01-05 9:24 ` [PATCH for v3.18.25 4/6] sched, rt: Convert switched_{from, to}_rt() / prio_changed_rt() to balance callbacks Byungchul Park
2016-01-05 9:24 ` [PATCH for v3.18.25 5/6] sched,dl: Remove return value from pull_dl_task() Byungchul Park
2016-01-05 9:24 ` [PATCH for v3.18.25 6/6] sched, dl: Convert switched_{from, to}_dl() / prio_changed_dl() to balance callbacks Byungchul Park
2016-03-01 8:15 ` [STABLE] kernel oops which can be fixed by peterz's patches Greg KH
2016-07-18 6:31 ` Byungchul Park
2016-07-18 12:09 ` Greg KH
2016-07-18 23:59 ` Byungchul Park
2016-06-13 18:31 ` Ben Hutchings
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