Re: [RFC 4/8] Make clear description of putback_lru_page

From: Minchan Kim
Date: Sun May 01 2011 - 11:10:19 EST


On Sun, May 1, 2011 at 10:13 PM, KOSAKI Motohiro
<kosaki.motohiro@xxxxxxxxxxxxxx> wrote:
>> On Thu, Apr 28, 2011 at 08:20:32AM +0900, Minchan Kim wrote:
>> > On Wed, Apr 27, 2011 at 5:11 PM, KAMEZAWA Hiroyuki
>> > <kamezawa.hiroyu@xxxxxxxxxxxxxx> wrote:
>> > > On Wed, 27 Apr 2011 01:25:21 +0900
>> > > Minchan Kim <minchan.kim@xxxxxxxxx> wrote:
>> > >
>> > >> Commonly, putback_lru_page is used with isolated_lru_page.
>> > >> The isolated_lru_page picks the page in middle of LRU and
>> > >> putback_lru_page insert the lru in head of LRU.
>> > >> It means it could make LRU churning so we have to be very careful.
>> > >> Let's clear description of putback_lru_page.
>> > >>
>> > >> Cc: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
>> > >> Cc: Mel Gorman <mgorman@xxxxxxx>
>> > >> Cc: Rik van Riel <riel@xxxxxxxxxx>
>> > >> Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
>> > >> Signed-off-by: Minchan Kim <minchan.kim@xxxxxxxxx>
>> > >
>> > > seems good...
>> > > Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
>> > >
>> > > But is there consensus which side of LRU is tail? head?
>> >
>> > I don't know. I used to think it's head.
>> > If other guys raise a concern as well, let's talk about it. :)
>> > Thanks
>>
>> I suppose we add new pages to the head of the LRU and reclaim old
>> pages from the tail.
>>
>> Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx>
>
> So, It would be better if isolate_lru_page() also have "LRU tail blah blah blah"
> comments.

Okay. I will try it.

>
> anyway,
> Â Â Â ÂReviewed-by: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
>

Thanks.


--
Kind regards,
Minchan Kim
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