From: "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>
To: Peter Zijlstra <peterz@infradead.org>,
Stephen Warren <swarren@wwwdotorg.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>,
LKML <linux-kernel@vger.kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Eric Dumazet <eric.dumazet@gmail.com>,
Ingo Molnar <mingo@kernel.org>, Kevin Hilman <khilman@linaro.org>,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
Thomas Gleixner <tglx@linutronix.de>,
Viresh Kumar <viresh.kumar@linaro.org>,
"linux-next@vger.kernel.org" <linux-next@vger.kernel.org>
Subject: Re: [PATCH 2/6] irq_work: Implement remote queueing
Date: Wed, 25 Jun 2014 22:27:24 +0530 [thread overview]
Message-ID: <53AAFF74.8090308@linux.vnet.ibm.com> (raw)
In-Reply-To: <20140625163820.GC3935@laptop>
On 06/25/2014 10:08 PM, Peter Zijlstra wrote:
> On Wed, Jun 25, 2014 at 10:23:21AM -0600, Stephen Warren wrote:
>> On 06/25/2014 04:19 AM, Peter Zijlstra wrote:
>>> On Wed, Jun 25, 2014 at 03:24:11PM +0530, Srivatsa S. Bhat wrote:
>>>> Wait, that was a stupid idea. hotplug_cfd() already invokes irq_work_run
>>>> indirectly via flush_smp_call_function_queue(). So irq_work_cpu_notify()
>>>> doesn't need to invoke it again, AFAIU. So perhaps we can get rid of
>>>> irq_work_cpu_notify() altogether?
>>>
>>> Just so...
>>>
>>> getting up at 6am and sitting in an airport terminal doesn't seem to
>>> agree with me; any more silly fail here?
>>>
>>> ---
>>> Subject: irq_work: Remove BUG_ON in irq_work_run()
>>> From: Peter Zijlstra <peterz@infradead.org>
>>> Date: Wed Jun 25 07:13:07 CEST 2014
>>>
>>> Because of a collision with 8d056c48e486 ("CPU hotplug, smp: flush any
>>> pending IPI callbacks before CPU offline"), which ends up calling
>>> hotplug_cfd()->flush_smp_call_function_queue()->irq_work_run(), which
>>> is not from IRQ context.
>>>
>>> And since that already calls irq_work_run() from the hotplug path,
>>> remove our entire hotplug handling.
>>
>> Tested-by: Stephen Warren <swarren@nvidia.com>
>>
>> [with the s/static// already mentioned in this thread, obviously:-)]
>
> Right; I pushed out a fixed version right before loosing my tubes at the
> airport :-)
>
> https://git.kernel.org/cgit/linux/kernel/git/peterz/queue.git/commit/?h=timers/nohz&id=921d8b81281ecdca686369f52165d04fa3505bd7
>
This version looks good.
Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Regards,
Srivatsa S. Bhat
> I've not gotten wu build bot spam on it so it must be good ;-)
>
> In any case, I'll add your tested-by and update later this evening.
>
next prev parent reply other threads:[~2014-06-25 16:59 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-06-10 15:15 [PATCH 0/6] nohz: Move nohz kick out of scheduler IPI, v8 Frederic Weisbecker
2014-06-10 15:15 ` [PATCH 1/6] irq_work: Split raised and lazy lists Frederic Weisbecker
2014-06-10 15:15 ` [PATCH 2/6] irq_work: Implement remote queueing Frederic Weisbecker
2014-06-24 20:33 ` Stephen Warren
2014-06-24 20:35 ` Stephen Warren
2014-06-25 5:12 ` Peter Zijlstra
2014-06-25 5:17 ` Peter Zijlstra
2014-06-25 6:37 ` Srivatsa S. Bhat
2014-06-25 9:36 ` Peter Zijlstra
2014-06-25 9:39 ` Peter Zijlstra
2014-06-25 9:50 ` Srivatsa S. Bhat
2014-06-25 9:54 ` Srivatsa S. Bhat
2014-06-25 10:19 ` Peter Zijlstra
2014-06-25 10:57 ` Srivatsa S. Bhat
2014-06-25 16:23 ` Stephen Warren
2014-06-25 16:38 ` Peter Zijlstra
2014-06-25 16:57 ` Srivatsa S. Bhat [this message]
2014-06-28 18:19 ` Borislav Petkov
2014-07-03 14:52 ` Frederic Weisbecker
2014-07-04 5:10 ` Sachin Kamat
2014-07-01 19:13 ` Stephen Warren
2014-06-10 15:15 ` [PATCH 3/6] nohz: Support nohz full remote kick Frederic Weisbecker
2014-06-10 15:15 ` [PATCH 4/6] nohz: Switch to nohz full remote kick on timer enqueue Frederic Weisbecker
2014-06-10 15:15 ` [PATCH 5/6] nohz: Use nohz own full kick on 2nd task enqueue Frederic Weisbecker
2014-06-10 15:15 ` [PATCH 6/6] nohz: Use IPI implicit full barrier against rq->nr_running r/w Frederic Weisbecker
2014-06-10 15:48 ` Peter Zijlstra
2014-06-10 16:24 ` Frederic Weisbecker
2014-06-10 15:48 ` [PATCH 0/6] nohz: Move nohz kick out of scheduler IPI, v8 Peter Zijlstra
2014-06-10 16:18 ` Frederic Weisbecker
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=53AAFF74.8090308@linux.vnet.ibm.com \
--to=srivatsa.bhat@linux.vnet.ibm.com \
--cc=akpm@linux-foundation.org \
--cc=eric.dumazet@gmail.com \
--cc=fweisbec@gmail.com \
--cc=khilman@linaro.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-next@vger.kernel.org \
--cc=mingo@kernel.org \
--cc=paulmck@linux.vnet.ibm.com \
--cc=peterz@infradead.org \
--cc=swarren@wwwdotorg.org \
--cc=tglx@linutronix.de \
--cc=viresh.kumar@linaro.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).