Re: PG_referenced and lru_cache (cpu%)...

[Rik van Riel <riel@conectiva.com.br>]

On Sat, 6 May 2000, Roger Larsson wrote:

> When _add_to_page_cache adds a page to the lru_cache
> it forces it to be referenced.
> In addition it will be added as youngest in list.

Which is IMHO a good thing, since the page *was* referenced
and was referenced last.

> When a page is needed it is very likely that a lot of
> the youngest pages are marked as referenced.

> order=0 is the only that tries to search the full list.

No. Referenced pages are not counted, so if we encounter
a lot of them we will happily age them all without decreasing
the value of count.

> When the shrink_mmap finds PG_referenced pages they are
> moved to local list young and will not be inserted before
> shink_mmap returns, again does not matter...

So the next time shrink_mmap() is called, we'll free the
page.

> Conclusion:

	[snip]

regards,

Rik
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