Re: [PATCH 4/4] mm: remove direct calling of migration

[Gioh Kim <gioh.kim@lge.com>]

2015-07-27 오후 10:58에 Vlastimil Babka 이(가) 쓴 글:
> On 07/13/2015 10:35 AM, Gioh Kim wrote:
>> From: Gioh Kim <gurugio@hanmail.net>
>>
>> Migration is completely generalized so that migrating mobile page
>> is processed with lru-pages in move_to_new_page.
>>
>> Signed-off-by: Gioh Kim <gioh.kim@lge.com>
>> Acked-by: Rafael Aquini <aquini@redhat.com>
>
> Why not just fold this to Patch 3? You already modify this hunk there, and prior to patch 3, the hunk was balloon-pages specific. You made it look generic only to remove it, which is unneeded code churn and I don't think it adds anything wrt e.g. bisectability.
Yes, you have a point.
I'll be merged into 3/4 at next spin.

I wanted to show the process how migration is generalized with this patch.
On second thought it is not necessary.

>
>> ---
>>   mm/migrate.c | 15 ---------------
>>   1 file changed, 15 deletions(-)
>>
>> diff --git a/mm/migrate.c b/mm/migrate.c
>> index 53f0081d..e6644ac 100644
>> --- a/mm/migrate.c
>> +++ b/mm/migrate.c
>> @@ -844,21 +844,6 @@ static int __unmap_and_move(struct page *page, struct page *newpage,
>>           }
>>       }
>>
>> -    if (unlikely(mobile_page(page))) {
>> -        /*
>> -         * A mobile page does not need any special attention from
>> -         * physical to virtual reverse mapping procedures.
>> -         * Skip any attempt to unmap PTEs or to remap swap cache,
>> -         * in order to avoid burning cycles at rmap level, and perform
>> -         * the page migration right away (proteced by page lock).
>> -         */
>> -        lock_page(newpage);
>> -        rc = page->mapping->a_ops->migratepage(page->mapping,
>> -                               newpage, page, mode);
>> -        unlock_page(newpage);
>> -        goto out_unlock;
>> -    }
>> -
>>       /*
>>        * Corner case handling:
>>        * 1. When a new swap-cache page is read into, it is added to the LRU
>>
>
>