Re: [PATCHv6 00/15] kill unnecessary bdi wakeups + cleanups

From: Jens Axboe
Date: Tue Aug 03 2010 - 08:48:04 EST


On 2010-08-03 14:37, Artem Bityutskiy wrote:
> On Tue, 2010-08-03 at 14:27 +0200, Jens Axboe wrote:
>> On 2010-07-25 13:29, Artem Bityutskiy wrote:
>>> Hi,
>>>
>>> here is v6 of the patch series which clean-ups bdi threads and substantially
>>> lessens amount of unnecessary kernel wake-ups, which is very important on
>>> battery-powered devices.
>>>
>>> This patch-set is also available at:
>>> git://git.infradead.org/users/dedekind/misc-2.6.git flushers_v6
>>
>> Thanks Artem, for sticking around long enough to get this into
>> shape. I have finally merged it.
>
> Thanks, but
>
>>> 1. Use 'spin_lock_bh' for the 'bdi->wb_lock' (changed patch N12)
>>
>> I'd rather not, question is how to avoid it. Either just wakeup the
>> default thread, or punt the lock-and-check bdi->wb.task to a thread.
>
> you merged this change, do you want me to send a separate patch which
> undo the 'spin_lock_bh' change? I'll think about how to avoid this and
> come back.

Yes, it's not a huge thing, but it would be nice to get rid of. So I
figured it was better to merge it and not have you respin the series yet
again.

--
Jens Axboe

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