From: Vivek Goyal <vgoyal-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
To: David Rientjes <rientjes-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
Cc: Prarit Bhargava <prarit-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>,
Andi Kleen <ak-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>,
Jonathan Corbet <corbet-T1hC0tSOHrs@public.gmane.org>,
jbaron-JqFfY2XvxFXQT0dZR+AlfA@public.gmane.org,
kexec-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org,
Rusty Russell <rusty-8n+1lVoiYb80n/F98K4Iww@public.gmane.org>,
linux-doc-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
Fabian Frederick <fabf-AgBVmzD5pcezQB+pC5nmwQ@public.gmane.org>,
isimatu.yasuaki-+CUm20s59erQFUHtdCDX3A@public.gmane.org,
"H. Peter Anvin" <hpa-YMNOUZJC4hwAvxtiuMwx3w@public.gmane.org>,
Masami Hiramatsu
<masami.hiramatsu.pt-FCd8Q96Dh0JBDgjK7y7TUQ@public.gmane.org>,
Andrew Morton
<akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>,
linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Subject: Re: [PATCH v8] kernel, add panic_on_warn
Date: Thu, 6 Nov 2014 17:07:31 -0500 [thread overview]
Message-ID: <20141106220731.GA13590@redhat.com> (raw)
In-Reply-To: <alpine.DEB.2.10.1411061352440.1526-X6Q0R45D7oAcqpCFd4KODRPsWskHk0ljAL8bYrjMMd8@public.gmane.org>
On Thu, Nov 06, 2014 at 01:57:36PM -0800, David Rientjes wrote:
[..]
> You see that doing
>
> if (panic_on_warn) {
> panic_on_warn = 0;
> panic(...);
> }
>
> is racy, I hope. If two threads WARN() at the same time, then there's
> nothing preventing a double panic() because WARN() itself is not
> serialized against anything. So both the current comment and your
> suggested revision comment are bogus.
panic() is serialized on panic_lock. So I guess it is fine to hit WARN()
on multiple cpus. Do you see an issue there?
Thanks
Vivek
next prev parent reply other threads:[~2014-11-06 22:07 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-11-05 11:42 [PATCH v8] kernel, add panic_on_warn Prarit Bhargava
[not found] ` <1415187736-16242-1-git-send-email-prarit-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2014-11-05 21:59 ` David Rientjes
[not found] ` <alpine.DEB.2.10.1411051357050.31575-X6Q0R45D7oAcqpCFd4KODRPsWskHk0ljAL8bYrjMMd8@public.gmane.org>
2014-11-06 13:10 ` Prarit Bhargava
[not found] ` <545B733C.6080903-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2014-11-06 21:57 ` David Rientjes
[not found] ` <alpine.DEB.2.10.1411061352440.1526-X6Q0R45D7oAcqpCFd4KODRPsWskHk0ljAL8bYrjMMd8@public.gmane.org>
2014-11-06 22:07 ` Vivek Goyal [this message]
[not found] ` <20141106220731.GA13590-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2014-11-06 22:52 ` Prarit Bhargava
2014-11-07 10:15 ` David Rientjes
[not found] ` <alpine.DEB.2.10.1411070214220.32405-X6Q0R45D7oAcqpCFd4KODRPsWskHk0ljAL8bYrjMMd8@public.gmane.org>
2014-11-07 11:05 ` Prarit Bhargava
2014-11-07 21:09 ` David Rientjes
[not found] ` <alpine.DEB.2.10.1411071306370.12192-X6Q0R45D7oAcqpCFd4KODRPsWskHk0ljAL8bYrjMMd8@public.gmane.org>
2014-11-08 13:29 ` Prarit Bhargava
2014-11-06 22:51 ` Prarit Bhargava
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