Message-ID: <4FA8FC83.7000503@nod.at>
Date: Tue, 08 May 2012 12:59:15 +0200
From: Richard Weinberger <richard@nod.at>
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To: dedekind1@gmail.com
CC: linux-mtd@lists.infradead.org, dwmw2@infradead.org,
        linux-kernel@vger.kernel.org, peterz@infradead.org
Subject: Re: [PATCH] UBI: Replace yield() with cond_resched()
References: <1336465602-12627-1-git-send-email-richard@nod.at> <1336467723.23308.23.camel@sauron.fi.intel.com>
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Am 08.05.2012 11:02, schrieb Artem Bityutskiy:
> On Tue, 2012-05-08 at 10:26 +0200, Richard Weinberger wrote:
>> The comment above yield()'s definition says:
>>  * If you want to use yield() to wait for something, use wait_event().=

>>  * If you want to use yield() to be 'nice' for others, use cond_resche=
d().
>>  * If you still want to use yield(), do not!
>>
>> The yield() usage of UBI really looks like the "be nice for others" ca=
se,
>> so use cond_resched().
>>
>> Signed-off-by: Richard Weinberger <richard@nod.at>
>> CC: peterz@infradead.org
>
> I guess we would better sleep for a couple of hundreds of milliseconds
> instead.

So, you'd prefer a msleep_interruptible(500) instead of yield() in this c=
ase?

> The purpose was different. If we have I/O error, we hope it is a
> transient failure. E.g., the HW is temporary unavailable because of an
> internal issue. And with yield() we hoped to schedule away for longer
> time than usual and let other processes which may affect that HW go
> forward and do something.

Okay, yield() is clearly the wrong choice here.
cond_resched() is better.

Thanks,
//richard


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