From: Sodagudi Prasad <psodagud@codeaurora.org>
To: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>,
mingo@kernel.org, gregkh@linuxfoundation.org,
bigeasy@linutronix.de, isaacm@codeaurora.org,
linux-kernel@vger.kernel.org
Subject: Re: cpu stopper threads and setaffinity leads to deadlock
Date: Fri, 03 Aug 2018 11:57:23 -0700 [thread overview]
Message-ID: <712493a7926b0f58543be052ced95db9@codeaurora.org> (raw)
In-Reply-To: <alpine.DEB.2.21.1808031340500.1745@nanos.tec.linutronix.de>
On 2018-08-03 04:41, Thomas Gleixner wrote:
> Prasad.
>
> On Thu, 2 Aug 2018, Peter Zijlstra wrote:
>>
>> So why didn't you do the 'obvious' parallel to what you did for
>> cpu_stop_queue_two_works(), namely:
>
> Is that patch fixing the issue for you?
<Prasad> Hi Thomas and Peter,
Yes. Tested both versions of patches and both variants are working on
Qualcomm devices
with stress testing of set affinity and tasks cross-migration, which
were previously leading to the deadlock.
-Thanks, Prasad
>
>> --- a/kernel/stop_machine.c
>> +++ b/kernel/stop_machine.c
>> @@ -81,6 +81,7 @@ static bool cpu_stop_queue_work(unsigned
>> unsigned long flags;
>> bool enabled;
>>
>> + preempt_disable();
>> raw_spin_lock_irqsave(&stopper->lock, flags);
>> enabled = stopper->enabled;
>> if (enabled)
>> @@ -90,6 +91,7 @@ static bool cpu_stop_queue_work(unsigned
>> raw_spin_unlock_irqrestore(&stopper->lock, flags);
>>
>> wake_up_q(&wakeq);
>> + preempt_enable();
>>
>> return enabled;
>> }
>>
--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora
Forum,
Linux Foundation Collaborative Project
prev parent reply other threads:[~2018-08-03 18:57 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-02 1:34 cpu stopper threads and setaffinity leads to deadlock Sodagudi Prasad
2018-08-02 8:12 ` Peter Zijlstra
2018-08-02 8:27 ` Mike Galbraith
2018-08-02 8:45 ` Peter Zijlstra
2018-08-02 9:49 ` Peter Zijlstra
2018-08-03 11:41 ` Thomas Gleixner
2018-08-03 18:57 ` Sodagudi Prasad [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=712493a7926b0f58543be052ced95db9@codeaurora.org \
--to=psodagud@codeaurora.org \
--cc=bigeasy@linutronix.de \
--cc=gregkh@linuxfoundation.org \
--cc=isaacm@codeaurora.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@kernel.org \
--cc=peterz@infradead.org \
--cc=tglx@linutronix.de \
/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).