From: "Srivatsa S. Bhat" <srivatsa.bhat@linux.vnet.ibm.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>, Tejun Heo <tj@kernel.org>,
akpm@linux-foundation.org, fweisbec@gmail.com,
paulmck@linux.vnet.ibm.com, tglx@linutronix.de, mingo@kernel.org,
rusty@rustcorp.com.au, hch@infradead.org, mgorman@suse.de,
riel@redhat.com, bp@suse.de, rostedt@goodmis.org,
mgalbraith@suse.de, ego@linux.vnet.ibm.com, rjw@rjwysocki.net,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v5 UPDATEDv3 3/3] CPU hotplug, smp: Flush any pending IPI callbacks before CPU offline
Date: Tue, 20 May 2014 16:01:37 +0530 [thread overview]
Message-ID: <537B2F09.5020306@linux.vnet.ibm.com> (raw)
In-Reply-To: <20140520102542.GW2485@laptop.programming.kicks-ass.net>
On 05/20/2014 03:55 PM, Peter Zijlstra wrote:
> On Tue, May 20, 2014 at 03:39:59PM +0530, Srivatsa S. Bhat wrote:
>>> The multi_cpu_stop() path isn't exclusive to hotplug, so your changelog
>>> is wrong or the patch is.
>>>
>>
>> Yes, I know that multi_cpu_stop() isn't exclusive to hotplug. That's why
>> I have explicitly referred to CPU hotplug in the comment as well as the
>> changelog.
>>
>> But I totally agree that code-wise this is not the best way to do it since
>> this affects (although harmlessly) usecases other than hotplug as well.
>>
>> Do you have any other suggestions?
>
> How about making a kernel/smp.c hotplug notifier and stuffing it in the
> CPU_DYING list? That's typically after we've already torn down the
> interrupts for that cpu, so no chance of any new ones coming in.
>
> Or is that too late?
>
No, that should work just fine. Thank you for the suggestion! I'll give
it a shot.
Regards,
Srivatsa S. Bhat
next prev parent reply other threads:[~2014-05-20 10:32 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-05-15 19:12 [PATCH v5 0/3] CPU hotplug: Fix the long-standing "IPI to offline CPU" issue Srivatsa S. Bhat
2014-05-15 19:13 ` [PATCH v5 1/3] smp: Print more useful debug info upon receiving IPI on an offline CPU Srivatsa S. Bhat
2014-05-15 19:19 ` Joe Perches
2014-05-15 19:34 ` Srivatsa S. Bhat
2014-05-15 19:43 ` Joe Perches
2014-05-15 19:51 ` [PATCH v5 UPDATED " Srivatsa S. Bhat
2014-05-15 19:13 ` [PATCH v5 2/3] CPU hotplug, stop-machine: Plug race-window that leads to "IPI-to-offline-CPU" Srivatsa S. Bhat
2014-05-15 19:17 ` Tejun Heo
2014-05-15 19:18 ` Srivatsa S. Bhat
2014-05-15 19:14 ` [PATCH v5 3/3] CPU hotplug, smp: Flush any pending IPI callbacks before CPU offline Srivatsa S. Bhat
2014-05-15 19:19 ` Tejun Heo
2014-05-15 19:26 ` Srivatsa S. Bhat
2014-05-15 19:36 ` Paul E. McKenney
2014-05-15 19:43 ` [PATCH v5 UPDATED " Srivatsa S. Bhat
2014-05-15 19:45 ` Tejun Heo
2014-05-19 12:19 ` [PATCH v5 UPDATEDv2 " Srivatsa S. Bhat
2014-05-19 16:18 ` Oleg Nesterov
2014-05-19 19:49 ` Srivatsa S. Bhat
2014-05-19 20:22 ` [PATCH v5 UPDATEDv3 " Srivatsa S. Bhat
2014-05-20 9:42 ` Peter Zijlstra
2014-05-20 10:09 ` Srivatsa S. Bhat
2014-05-20 10:25 ` Peter Zijlstra
2014-05-20 10:31 ` Srivatsa S. Bhat [this message]
2014-05-20 10:38 ` Srivatsa S. Bhat
2014-05-20 10:42 ` Srivatsa S. Bhat
2014-05-15 19:44 ` [PATCH v5 " Tejun Heo
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