Re: [PATCH] 2.2.17pre7 VM enhancement Re: I/O performance on

[Manfred Spraul <manfred@colorfullife.com>]

Rik van Riel wrote:
> 
> 
> Actually, FreeBSD has a special case in the page fault code
> for sequential accesses and I believe we must have that too.
> 

Where is that code? I found a sysctl parameter vm_pageout_algorithm_lru,
but nothing else.

> Both LRU and LFU break down on linear accesses to an array
> that doesn't fit in memory. In that case you really want
> MRU replacement, with some simple code that "detects the
> window size" you need to keep in memory. This seems to be
> the only way to get any speedup on such programs when you
> increase memory size to something which is still smaller
> than the total program size.
> 

Do you have an idea how to detect that situation?

--
	Manfred
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