Re: [PATCH v2] mm, page_alloc: enable pcpu_drain with zone capability

[Wei Yang <richard.weiyang@gmail.com>]

On Wed, Dec 12, 2018 at 03:47:02PM +0100, Oscar Salvador wrote:
>On Wed, Dec 12, 2018 at 10:25:50PM +0800, Wei Yang wrote:
>> drain_all_pages is documented to drain per-cpu pages for a given zone (if
>> non-NULL). The current implementation doesn't match the description though.
>> It will drain all pcp pages for all zones that happen to have cached pages
>> on the same cpu as the given zone. This will leave to premature pcp cache
>> draining for zones that are not of an interest for the caller - e.g.
>> compaction, hwpoison or memory offline.
>> 
>> This would force the page allocator to take locks and potential lock
>> contention as a result.
>> 
>> There is no real reason for this sub-optimal implementnation. Replace
>> per-cpu work item with a dedicated structure which contains a pointer to
>> zone and pass it over to the worker. This will get the zone information all
>> the way down to the worker function and do the right job.
>> 
>> [mhocko@suse.com: refactor the whole changelog]
>> 
>> Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
>> Acked-by: Michal Hocko <mhocko@suse.com>
>
>Looks to me
>
>Reviewed-by: Oscar Salvador <osalvador@suse.de>
>
>thanks

Thanks :-)

>
>-- 
>Oscar Salvador
>SUSE L3

-- 
Wei Yang
Help you, Help me