From: Thomas Gleixner <tglx@linutronix.de>
To: Borislav Petkov <bp@alien8.de>
Cc: "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>,
Dave Hansen <dave@sr71.net>, LKML <linux-kernel@vger.kernel.org>,
Dave Jones <davej@redhat.com>,
dhillf@gmail.com, Peter Zijlstra <peterz@infradead.org>
Subject: Re: kernel BUG at kernel/smpboot.c:134!
Date: Mon, 8 Apr 2013 11:24:14 +0200 (CEST) [thread overview]
Message-ID: <alpine.LFD.2.02.1304081122040.21884@ionos> (raw)
In-Reply-To: <20130407095025.GA31307@pd.tnic>
On Sun, 7 Apr 2013, Borislav Petkov wrote:
> On Sun, Apr 07, 2013 at 11:20:10AM +0200, Thomas Gleixner wrote:
> > And it's even more bogus because the cpu to which we would bind in
> > kthread_create_on_cpu() is not yet online.
>
> In case you guys are wondering about reproducibility, I saw the same
> BUG_ON yesterday on a 32-bit atom smp qemu guest too (don't ask why?
> :-))
I don't have to ask. It's caused by massive brain failure on my side.
Does the patch below fix the issue ?
Thanks,
tglx
---
Index: linux-2.6/kernel/kthread.c
===================================================================
--- linux-2.6.orig/kernel/kthread.c
+++ linux-2.6/kernel/kthread.c
@@ -131,8 +131,14 @@ static void __kthread_parkme(struct kthr
schedule();
__set_current_state(TASK_INTERRUPTIBLE);
}
- clear_bit(KTHREAD_IS_PARKED, &self->flags);
__set_current_state(TASK_RUNNING);
+ clear_bit(KTHREAD_IS_PARKED, &self->flags);
+
+ /* Rebind ourself to the target cpu */
+ if (test_bit(KTHREAD_IS_PER_CPU, &self->flags)) {
+ set_cpus_allowed_ptr(currrent, cpumask_of(self->cpu));
+ current->flags |= PF_THREAD_BOUND;
+ }
}
void kthread_parkme(void)
@@ -344,11 +350,8 @@ void kthread_unpark(struct task_struct *
* park before that happens we'd see the IS_PARKED bit
* which might be about to be cleared.
*/
- if (test_and_clear_bit(KTHREAD_IS_PARKED, &kthread->flags)) {
- if (test_bit(KTHREAD_IS_PER_CPU, &kthread->flags))
- __kthread_bind(k, kthread->cpu);
+ if (test_and_clear_bit(KTHREAD_IS_PARKED, &kthread->flags))
wake_up_process(k);
- }
}
put_task_struct(k);
}
next prev parent reply other threads:[~2013-04-08 9:24 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-04-05 21:43 kernel BUG at kernel/smpboot.c:134! Dave Hansen
2013-04-06 7:12 ` Srivatsa S. Bhat
2013-04-06 8:31 ` Thomas Gleixner
2013-04-07 9:20 ` Thomas Gleixner
2013-04-07 9:50 ` Borislav Petkov
2013-04-08 9:24 ` Thomas Gleixner [this message]
2013-04-08 11:55 ` Borislav Petkov
2013-04-08 12:17 ` Thomas Gleixner
2013-04-09 14:38 ` [PATCH] kthread: Prevent unpark race which puts threads on the wrong cpu Thomas Gleixner
2013-04-09 15:55 ` Dave Hansen
2013-04-09 18:43 ` Thomas Gleixner
2013-04-09 19:30 ` Thomas Gleixner
2013-04-09 20:38 ` Dave Hansen
2013-04-09 20:54 ` Dave Hansen
2013-04-10 8:29 ` Thomas Gleixner
2013-04-10 10:51 ` Thomas Gleixner
2013-04-10 19:41 ` Dave Hansen
2013-04-11 10:19 ` Thomas Gleixner
2013-04-11 10:48 ` Srivatsa S. Bhat
2013-04-11 11:43 ` Srivatsa S. Bhat
2013-04-11 11:59 ` Srivatsa S. Bhat
2013-04-11 12:51 ` Thomas Gleixner
2013-04-11 12:54 ` Thomas Gleixner
2013-04-11 13:46 ` Thomas Gleixner
2013-04-11 18:07 ` Dave Hansen
2013-04-11 19:48 ` Thomas Gleixner
2013-04-10 14:03 ` [PATCH] CPU hotplug, smpboot: Fix crash in smpboot_thread_fn() Srivatsa S. Bhat
2013-04-11 8:10 ` Thomas Gleixner
2013-04-11 10:19 ` Srivatsa S. Bhat
2013-04-11 19:16 ` [PATCH] kthread: Prevent unpark race which puts threads on the wrong cpu Srivatsa S. Bhat
2013-04-11 20:47 ` Thomas Gleixner
2013-04-11 21:19 ` Srivatsa S. Bhat
2013-04-12 10:59 ` Thomas Gleixner
2013-04-12 11:26 ` Srivatsa S. Bhat
2013-04-15 19:49 ` Dave Hansen
2013-04-12 10:41 ` Peter Zijlstra
2013-04-12 12:32 ` [tip:core/urgent] " tip-bot for Thomas Gleixner
2014-09-23 0:09 kernel BUG at kernel/smpboot.c:134! Brian Norris
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=alpine.LFD.2.02.1304081122040.21884@ionos \
--to=tglx@linutronix.de \
--cc=bp@alien8.de \
--cc=dave@sr71.net \
--cc=davej@redhat.com \
--cc=dhillf@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=peterz@infradead.org \
--cc=srivatsa.bhat@linux.vnet.ibm.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).