Re: [PATCH 1/2] cfq-iosched: remove dead_key from cfq_io_context

From: Jens Axboe
Date: Fri May 21 2010 - 13:34:15 EST

On Fri, May 21 2010, Konstantin Khlebnikov wrote:
> On 21.05.2010 13:40, Jens Axboe wrote:
>> On Thu, May 20 2010, Konstantin Khlebnikov wrote:
>>> Remove ->dead_key field from cfq_io_context to shrink its size to 128 bytes.
>>> (64 bytes for 32-bit hosts)
>>> Use lower bit in ->key as dead-mark, instead of moving key to separate field.
>>> After this for dead cfq_io_context we got cic->key != cfqd automatically.
>>> Thus, io_context's last-hit cache should work without changing.
>>> Now to check ->key for non-dead state compare it with cfqd,
>>> instead of checking ->key for non-null value as it was before.
>>> Plus remove obsolete race protection in cfq_cic_lookup.
>>> This race gone after v2.6.24-1728-g4ac845a
>> This, and the second patch, look really good. How much testing have you
>> done with it?
> I have run multiple fsstress and simultaneously switch io-scheduler in loop
> for several hours, no oopses and leaks detected.

OK, I'll queue it up for later in the 2.6.35 cycle.

Jens Axboe

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