On 06/19/2013 04:53 PM, Mel Gorman wrote:
> On Wed, Jun 19, 2013 at 02:55:13PM +0800, Chen Gang wrote:
>> >
>> > 'lru' may be used without initialized, so need regressing part of the
>> > related patch.
>> >
>> > The related patch:
>> > "3abf380 mm: remove lru parameter from __lru_cache_add and lru_cache_add_lru"
>> >
>> >
>> > Signed-off-by: Chen Gang <gang.chen@xxxxxxxxxxx>
>> > ---
>> > mm/vmscan.c | 1 +
>> > 1 files changed, 1 insertions(+), 0 deletions(-)
>> >
>> > diff --git a/mm/vmscan.c b/mm/vmscan.c
>> > index fe73724..e92b1858 100644
>> > --- a/mm/vmscan.c
>> > +++ b/mm/vmscan.c
>> > @@ -595,6 +595,7 @@ redo:
>> > * unevictable page on [in]active list.
>> > * We know how to handle that.
>> > */
>> > + lru = !!TestClearPageActive(page) + page_lru_base_type(page);
>> > lru_cache_add(page);
> Thanks for catching this but I have one question. Why are you clearing
> the active bit?
>
Oh, it is my fault, I only want to regress part of the original patch,
did not notice clearing the active bit.
> Before 3abf380 we did
>
> active = TestClearPageActive(page);
> lru = active + page_lru_base_type(page);
> lru_cache_add_lru(page, lru);
>
> so if the page was active before then it gets added to the active list. When
> 3abf380 is applied. it becomes.
>
> Leave PageActive alone
> lru_cache_add(page);
> .... until __pagevec_lru_add -> __pagevec_lru_add_fn
> int file = page_is_file_cache(page);
> int active = PageActive(page);
> enum lru_list lru = page_lru(page);
>
> After your patch it's
>
> Clear PageActive
> lru_cache_add(page)
> ......
> always add to inactive list
>
> I do not think you intended to do this and if you did, it deserves far
> more comment than being a compile warning fix. In putback_lru_page we only
> care about whether the lru was unevictable or not. Hence I think what you
> meant to do was simply
>
> lru = page_lru_base_type(page);
>
> If you agree then can you resend a revised version to Andrew please?
Yes, I should do, but excuse me, I do not quite know about 'revised
version'.
I guess it means I need still send the related patch which base on the
original one, e.g. for next-20130618:
------------------------diff begin-------------------------------------
diff --git a/mm/vmscan.c b/mm/vmscan.c
index fe73724..d03facb 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -595,6 +595,7 @@ redo:
* unevictable page on [in]active list.
* We know how to handle that.
*/
+ lru = page_lru_base_type(page);
lru_cache_add(page);
} else {
/*
------------------------diff end---------------------------------------
Is it correct ?
Thanks.
--
Chen Gang
Asianux Corporation
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