Re: [PATCH] mm: evict streaming IO cache first

[Rik van Riel <riel@redhat.com>]

KAMEZAWA Hiroyuki wrote:
> On Mon, 17 Nov 2008 16:03:48 +0900
> "KOSAKI Motohiro" <kosaki.motohiro@jp.fujitsu.com> wrote:
>>> How about resetting zone->recent_scanned/rotated to be some value calculated from
>>> INACTIVE_ANON/INACTIVE_FILE at some time (when the system is enough idle) ?
>> in get_scan_ratio()
>>
> But active/inactive ratio (and mapped_ratio) is not handled there.
> 
> Follwoing 2 will return the same scan ratio.

get_scan_ratio does not look at the sizes of the lists, but
at the ratio between "pages scanned" and "pages rotated".

A page that is moved from the inactive to the active list
is always counted as rotated.

A page that is moved from the active to the inactive list
is counted as rotated if it was mapped and referenced.

> ==case 1==
>   active_anon = 480M
>   inactive_anon = 32M
>   active_file = 2M
>   inactive_file = 510M
> 
> ==case 2==
>   active_anon = 480M
>   inactive_anon = 32M
>   active_file = 480M
>   inactive_file = 32M
> ==
> 
> 
> 
> -Kame
> 


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