Message-ID: <52FC99F8.4020002@linux.vnet.ibm.com>
Date: Thu, 13 Feb 2014 15:40:00 +0530
From: Preeti U Murthy <preeti@linux.vnet.ibm.com>
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To: Alex Shi <alex.shi@linaro.org>
CC: Daniel Lezcano <daniel.lezcano@linaro.org>,
        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>
In-Reply-To: <52FC7835.1090509@linaro.org>
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Sender: linux-kernel-owner@vger.kernel.org

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>
> 

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