Re: [PATCH v4] page_alloc: consider highatomic reserve in watermark fast

2020-06-23 Thread Michal Hocko
On Mon 22-06-20 17:25:01, Mel Gorman wrote: > On Mon, Jun 22, 2020 at 04:23:04PM +0200, Michal Hocko wrote: > > On Mon 22-06-20 11:04:39, Mel Gorman wrote: > > > On Mon, Jun 22, 2020 at 06:40:20PM +0900, ? wrote: > > > > >But more importantly, I have hard time to follow why we need both > >

Re: [PATCH v4] page_alloc: consider highatomic reserve in watermark fast

2020-06-22 Thread Mel Gorman
On Mon, Jun 22, 2020 at 04:23:04PM +0200, Michal Hocko wrote: > On Mon 22-06-20 11:04:39, Mel Gorman wrote: > > On Mon, Jun 22, 2020 at 06:40:20PM +0900, ? wrote: > > > >But more importantly, I have hard time to follow why we need both > > > >zone_watermark_fast and zone_watermark_ok now. T

Re: [PATCH v4] page_alloc: consider highatomic reserve in watermark fast

2020-06-22 Thread Michal Hocko
On Mon 22-06-20 11:04:39, Mel Gorman wrote: > On Mon, Jun 22, 2020 at 06:40:20PM +0900, ? wrote: > > >But more importantly, I have hard time to follow why we need both > > >zone_watermark_fast and zone_watermark_ok now. They should be > > >essentially the same for anything but order == 0. F

Re: [PATCH v4] page_alloc: consider highatomic reserve in watermark fast

2020-06-22 Thread Mel Gorman
On Mon, Jun 22, 2020 at 06:40:20PM +0900, ? wrote: > >But more importantly, I have hard time to follow why we need both > >zone_watermark_fast and zone_watermark_ok now. They should be > >essentially the same for anything but order == 0. For order 0 the > >only difference between the two is

RE: [PATCH v4] page_alloc: consider highatomic reserve in watermark fast

2020-06-22 Thread 김재원
>On Sat 20-06-20 08:59:58, Jaewon Kim wrote: >[...] >> @@ -3502,19 +3525,12 @@ bool __zone_watermark_ok(struct zone *z, unsigned >> int order, unsigned long mark, >> const bool alloc_harder = (alloc_flags & (ALLOC_HARDER|ALLOC_OOM)); >> >> /* free_pages may go negative - that's

Re: [PATCH v4] page_alloc: consider highatomic reserve in watermark fast

2020-06-22 Thread Michal Hocko
On Sat 20-06-20 08:59:58, Jaewon Kim wrote: [...] > @@ -3502,19 +3525,12 @@ bool __zone_watermark_ok(struct zone *z, unsigned int > order, unsigned long mark, > const bool alloc_harder = (alloc_flags & (ALLOC_HARDER|ALLOC_OOM)); > > /* free_pages may go negative - that's OK */ > -

Re: [PATCH v4] page_alloc: consider highatomic reserve in watermark fast

2020-06-22 Thread Mel Gorman
On Sat, Jun 20, 2020 at 08:59:58AM +0900, Jaewon Kim wrote: > zone_watermark_fast was introduced by commit 48ee5f3696f6 ("mm, > page_alloc: shortcut watermark checks for order-0 pages"). The commit > simply checks if free pages is bigger than watermark without additional > calculation such like red

Re: [PATCH v4] page_alloc: consider highatomic reserve in watermark fast

2020-06-19 Thread Baoquan He
On 06/20/20 at 08:59am, Jaewon Kim wrote: ... > kswapd0-1207 [005] ...1 889.213398: mm_page_alloc: page= (null) pfn=0 > order=0 migratetype=1 nr_free=3650 > gfp_flags=GFP_NOWAIT|__GFP_HIGHMEM|__GFP_NOWARN|__GFP_MOVABLE > > Reported-by: Yong-Taek Lee > Suggested-by: Minchan Kim > Signed-off