Re: [patch] mm: more likely reclaim MADV_SEQUENTIAL mappings II

[Johannes Weiner <hannes@saeurebad.de>]

Johannes Weiner <hannes@saeurebad.de> writes:

> Andrew Morton <akpm@linux-foundation.org> writes:
>
>> On Tue, 21 Oct 2008 13:33:45 +0200
>> Johannes Weiner <hannes@saeurebad.de> wrote:
>>
>>> File pages mapped only in sequentially read mappings are perfect
>>> reclaim canditates.
>>> 
>>> This makes MADV_SEQUENTIAL mappings behave like a weak references,
>>> their pages will be reclaimed unless they have a strong reference from
>>> a normal mapping as well.
>>> 
>>> The patch changes the reclaim and the unmap path where they check if
>>> the page has been referenced.  In both cases, accesses through
>>> sequentially read mappings will be ignored.
>>> 
>>> Signed-off-by: Johannes Weiner <hannes@saeurebad.de>
>>> ---
>>> II: add likely()s to mitigate the extra branches a bit as to Nick's
>>>     suggestion
>>
>> Is http://hannes.saeurebad.de/madvseq/ still true with this version?
>
> No, sorry, still running benchmarks on this version.  Coming up
> soon...

Ok, reran the tests I used for the data on this website and updated it.
Take a look.  I am quite overwhelmed by the results, hehe.

Kosaki-san, could you perhaps run the tests you did for the previous
patch on this one, too?  I am not getting any stable results for
throughput measuring...

> 	Hannes

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