From: Shan Hai <haishan.bai@gmail.com>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: akpm@linux-foundation.org, eric.dumazet@gmail.com,
vapier@gentoo.org, asharma@fb.com, linux-kernel@vger.kernel.org,
linux-rt-users@vger.kernel.org
Subject: Re: [PATCH V2 1/1] lib/atomic64 using raw_spin_lock_irq[save|resotre] for atomicity
Date: Fri, 02 Sep 2011 08:48:33 +0800 [thread overview]
Message-ID: <4E6027E1.1090905@gmail.com> (raw)
In-Reply-To: <alpine.LFD.2.02.1109011209000.2723@ionos>
On 09/01/2011 06:11 PM, Thomas Gleixner wrote:
> On Thu, 1 Sep 2011, Thomas Gleixner wrote:
>
>> On Thu, 1 Sep 2011, Shan Hai wrote:
>>
>>> The spin_lock_irq[save|restore] could break the atomicity of the
>>> atomic64_* operations in the PREEMPT-RT configuration, because
>>> the spin_lock_irq[save|restore] themselves are preemptable in the
>>> PREEMPT-RT, using raw variant of the spin lock could provide the
>>> atomicity that atomic64_* need.
>> Good catch. Queued for the next release.
> Though the changelog is misleading. The reason is not that they are
> preemtible.
>
> The reason for your OOPs is that the sleeping locks are not IRQ
> safe. And your system simply deadlocked due to that.
>
Will correct it in the V3 patch, thanks for the advice.
Cheers
Shan Hai
> Thanks,
>
> tglx
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/
prev parent reply other threads:[~2011-09-02 0:48 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-09-01 3:32 [PATCH V2 0/1] lib/atomic64 using raw_spin_lock_irq[save|resotre] for atomicity Shan Hai
2011-09-01 3:32 ` [PATCH V2 1/1] " Shan Hai
2011-09-01 5:27 ` Yong Zhang
2011-09-01 9:59 ` Thomas Gleixner
2011-09-01 10:11 ` Thomas Gleixner
2011-09-02 0:48 ` Shan Hai [this message]
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=4E6027E1.1090905@gmail.com \
--to=haishan.bai@gmail.com \
--cc=akpm@linux-foundation.org \
--cc=asharma@fb.com \
--cc=eric.dumazet@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-rt-users@vger.kernel.org \
--cc=tglx@linutronix.de \
--cc=vapier@gentoo.org \
/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).