From: Aubrey Li <aubrey.intel@gmail.com>
To: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Subhra Mazumdar <subhra.mazumdar@oracle.com>,
Mel Gorman <mgorman@techsingularity.net>,
Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Paul Turner <pjt@google.com>,
Linux List Kernel Mailing <linux-kernel@vger.kernel.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
"Fr?d?ric Weisbecker" <fweisbec@gmail.com>,
Kees Cook <keescook@chromium.org>, Greg Kerr <kerrnel@google.com>
Subject: Re: [RFC][PATCH 00/16] sched: Core scheduling
Date: Thu, 14 Mar 2019 13:30:03 +0800 [thread overview]
Message-ID: <CAERHkrvFe-s=_SD2WO0yuYiQ3JxY22=pSrM4UE-BWpbPD8iiCA@mail.gmail.com> (raw)
In-Reply-To: <8098aac2-60f7-6fe9-2a3a-2fe2e1b49bde@linux.intel.com>
On Thu, Mar 14, 2019 at 8:35 AM Tim Chen <tim.c.chen@linux.intel.com> wrote:
> >>
> >> One more NULL pointer dereference:
> >>
> >> Mar 12 02:24:46 aubrey-ivb kernel: [ 201.916741] core sched enabled
> >> [ 201.950203] BUG: unable to handle kernel NULL pointer dereference
> >> at 0000000000000008
> >> [ 201.950254] ------------[ cut here ]------------
> >> [ 201.959045] #PF error: [normal kernel read fault]
> >> [ 201.964272] !se->on_rq
> >> [ 201.964287] WARNING: CPU: 22 PID: 2965 at kernel/sched/fair.c:6849
> >> set_next_buddy+0x52/0x70
> >
> Shouldn't the for_each_sched_entity(se) skip the code block for !se case
> have avoided null pointer access of se?
>
> Since
> #define for_each_sched_entity(se) \
> for (; se; se = se->parent)
>
> Scratching my head a bit here on how your changes would have made
> a difference.
This NULL pointer dereference is not replicable, which makes me thought the
change works...
>
> In your original log, I wonder if the !se->on_rq warning on CPU 22 is mixed with the actual OOPs?
> Saw also in your original log rb_insert_color. Wonder if that
> was actually the source of the Oops?
No chance to figure this out, I only saw this once, lockup occurs more
frequently.
Thanks,
-Aubrey
next prev parent reply other threads:[~2019-03-14 5:30 UTC|newest]
Thread overview: 99+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-18 16:56 [RFC][PATCH 00/16] sched: Core scheduling Peter Zijlstra
2019-02-18 16:56 ` [RFC][PATCH 01/16] stop_machine: Fix stop_cpus_in_progress ordering Peter Zijlstra
2019-02-18 16:56 ` [RFC][PATCH 02/16] sched: Fix kerneldoc comment for ia64_set_curr_task Peter Zijlstra
2019-02-18 16:56 ` [RFC][PATCH 03/16] sched: Wrap rq::lock access Peter Zijlstra
2019-02-19 16:13 ` Phil Auld
2019-02-19 16:22 ` Peter Zijlstra
2019-02-19 16:37 ` Phil Auld
2019-03-18 15:41 ` Julien Desfossez
2019-03-20 2:29 ` Subhra Mazumdar
2019-03-21 21:20 ` Julien Desfossez
2019-03-22 13:34 ` Peter Zijlstra
2019-03-22 20:59 ` Julien Desfossez
2019-03-23 0:06 ` Subhra Mazumdar
2019-03-27 1:02 ` Subhra Mazumdar
2019-03-29 13:35 ` Julien Desfossez
2019-03-29 22:23 ` Subhra Mazumdar
2019-04-01 21:35 ` Subhra Mazumdar
2019-04-03 20:16 ` Julien Desfossez
2019-04-05 1:30 ` Subhra Mazumdar
2019-04-02 7:42 ` Peter Zijlstra
2019-03-22 23:28 ` Tim Chen
2019-03-22 23:44 ` Tim Chen
2019-02-18 16:56 ` [RFC][PATCH 04/16] sched/{rt,deadline}: Fix set_next_task vs pick_next_task Peter Zijlstra
2019-02-18 16:56 ` [RFC][PATCH 05/16] sched: Add task_struct pointer to sched_class::set_curr_task Peter Zijlstra
2019-02-18 16:56 ` [RFC][PATCH 06/16] sched/fair: Export newidle_balance() Peter Zijlstra
2019-02-18 16:56 ` [RFC][PATCH 07/16] sched: Allow put_prev_task() to drop rq->lock Peter Zijlstra
2019-02-18 16:56 ` [RFC][PATCH 08/16] sched: Rework pick_next_task() slow-path Peter Zijlstra
2019-02-18 16:56 ` [RFC][PATCH 09/16] sched: Introduce sched_class::pick_task() Peter Zijlstra
2019-02-18 16:56 ` [RFC][PATCH 10/16] sched: Core-wide rq->lock Peter Zijlstra
2019-02-18 16:56 ` [RFC][PATCH 11/16] sched: Basic tracking of matching tasks Peter Zijlstra
2019-02-18 16:56 ` [RFC][PATCH 12/16] sched: A quick and dirty cgroup tagging interface Peter Zijlstra
2019-02-18 16:56 ` [RFC][PATCH 13/16] sched: Add core wide task selection and scheduling Peter Zijlstra
[not found] ` <20190402064612.GA46500@aaronlu>
2019-04-02 8:28 ` Peter Zijlstra
2019-04-02 13:20 ` Aaron Lu
2019-04-05 14:55 ` Aaron Lu
2019-04-09 18:09 ` Tim Chen
2019-04-10 4:36 ` Aaron Lu
2019-04-10 14:18 ` Aubrey Li
2019-04-11 2:11 ` Aaron Lu
2019-04-10 14:44 ` Peter Zijlstra
2019-04-11 3:05 ` Aaron Lu
2019-04-11 9:19 ` Peter Zijlstra
2019-04-10 8:06 ` Peter Zijlstra
2019-04-10 19:58 ` Vineeth Remanan Pillai
2019-04-15 16:59 ` Julien Desfossez
2019-04-16 13:43 ` Aaron Lu
2019-04-09 18:38 ` Julien Desfossez
2019-04-10 15:01 ` Peter Zijlstra
2019-04-11 0:11 ` Subhra Mazumdar
2019-04-19 8:40 ` Ingo Molnar
2019-04-19 23:16 ` Subhra Mazumdar
2019-02-18 16:56 ` [RFC][PATCH 14/16] sched/fair: Add a few assertions Peter Zijlstra
2019-02-18 16:56 ` [RFC][PATCH 15/16] sched: Trivial forced-newidle balancer Peter Zijlstra
2019-02-21 16:19 ` Valentin Schneider
2019-02-21 16:41 ` Peter Zijlstra
2019-02-21 16:47 ` Peter Zijlstra
2019-02-21 18:28 ` Valentin Schneider
2019-04-04 8:31 ` Aubrey Li
2019-04-06 1:36 ` Aubrey Li
2019-02-18 16:56 ` [RFC][PATCH 16/16] sched: Debug bits Peter Zijlstra
2019-02-18 17:49 ` [RFC][PATCH 00/16] sched: Core scheduling Linus Torvalds
2019-02-18 20:40 ` Peter Zijlstra
2019-02-19 0:29 ` Linus Torvalds
2019-02-19 15:15 ` Ingo Molnar
2019-02-22 12:17 ` Paolo Bonzini
2019-02-22 14:20 ` Peter Zijlstra
2019-02-22 19:26 ` Tim Chen
2019-02-26 8:26 ` Aubrey Li
2019-02-27 7:54 ` Aubrey Li
2019-02-21 2:53 ` Subhra Mazumdar
2019-02-21 14:03 ` Peter Zijlstra
2019-02-21 18:44 ` Subhra Mazumdar
2019-02-22 0:34 ` Subhra Mazumdar
2019-02-22 12:45 ` Mel Gorman
2019-02-22 16:10 ` Mel Gorman
2019-03-08 19:44 ` Subhra Mazumdar
2019-03-11 4:23 ` Aubrey Li
2019-03-11 18:34 ` Subhra Mazumdar
2019-03-11 23:33 ` Subhra Mazumdar
2019-03-12 0:20 ` Greg Kerr
2019-03-12 0:47 ` Subhra Mazumdar
2019-03-12 7:33 ` Aaron Lu
2019-03-12 7:45 ` Aubrey Li
2019-03-13 5:55 ` Aubrey Li
2019-03-14 0:35 ` Tim Chen
2019-03-14 5:30 ` Aubrey Li [this message]
2019-03-14 6:07 ` Li, Aubrey
2019-03-18 6:56 ` Aubrey Li
2019-03-12 19:07 ` Pawan Gupta
2019-03-26 7:32 ` Aaron Lu
2019-03-26 7:56 ` Aaron Lu
2019-02-19 22:07 ` Greg Kerr
2019-02-20 9:42 ` Peter Zijlstra
2019-02-20 18:33 ` Greg Kerr
2019-02-22 14:10 ` Peter Zijlstra
2019-03-07 22:06 ` Paolo Bonzini
2019-02-20 18:43 ` Subhra Mazumdar
2019-03-01 2:54 ` Subhra Mazumdar
2019-03-14 15:28 ` Julien Desfossez
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