Message-ID: <52FC9CE9.8000700@linaro.org>
Date: Thu, 13 Feb 2014 11:22:33 +0100
From: Daniel Lezcano <daniel.lezcano@linaro.org>
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To: Preeti U Murthy <preeti@linux.vnet.ibm.com>,
        Alex Shi <alex.shi@linaro.org>
CC: Preeti Murthy <preeti.lkml@gmail.com>,
        Peter Zijlstra <peterz@infradead.org>, mingo@kernel.org,
        LKML <linux-kernel@vger.kernel.org>,
        Lists linaro-kernel <linaro-kernel@lists.linaro.org>
Subject: Re: [PATCH V2 2/3] sched: Fix race in idle_balance()
References: <1391728237-4441-1-git-send-email-daniel.lezcano@linaro.org> <1391728237-4441-3-git-send-email-daniel.lezcano@linaro.org> <CAM4v1pMEFTe6pQVDFzaXmqt_A3vw3tyj7Ewqib6zbzH++YzY3w@mail.gmail.com> <52FA0577.6080607@linaro.org> <52FC7835.1090509@linaro.org> <52FC99F8.4020002@linux.vnet.ibm.com>
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On 02/13/2014 11:10 AM, Preeti U Murthy wrote:
> Hi,
>
> On 02/13/2014 01:15 PM, Alex Shi wrote:
>> On 02/11/2014 07:11 PM, Daniel Lezcano wrote:
>>> On 02/10/2014 10:24 AM, Preeti Murthy wrote:
>>>> HI Daniel,
>>>>
>>>> Isn't the only scenario where another cpu can put an idle task on
>>>> our runqueue,
>>>
>>> Well, I am not sure to understand what you meant, but I assume you are
>>> asking if it is possible to have a task to be pulled when we are idle,
>>> right ?
>>>
>>> This patch fixes the race when the current cpu is *about* to enter idle
>>> when calling schedule().
>>
>> Preeti said the she didn't see a possible to insert a task on the cpu.
>>
>> I also did a quick check, maybe task come from wakeup path?
>
> Yes this is possible. Thanks for pointing this :)
>
> Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>

Thanks for the review !

   -- Daniel


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