Re: [PATCH 4/5] mm: vmscan: only write dirty pages that the scanner has seen twice

2017-01-26 Thread Michal Hocko
On Mon 23-01-17 13:16:40, Johannes Weiner wrote: > Dirty pages can easily reach the end of the LRU while there are still > clean pages to reclaim around. Don't let kswapd write them back just > because there are a lot of them. It costs more CPU to find the clean > pages, but that's almost

Re: [PATCH 4/5] mm: vmscan: only write dirty pages that the scanner has seen twice

2017-01-26 Thread Michal Hocko
On Mon 23-01-17 13:16:40, Johannes Weiner wrote: > Dirty pages can easily reach the end of the LRU while there are still > clean pages to reclaim around. Don't let kswapd write them back just > because there are a lot of them. It costs more CPU to find the clean > pages, but that's almost

Re: [PATCH 4/5] mm: vmscan: only write dirty pages that the scanner has seen twice

2017-01-26 Thread Mel Gorman
On Mon, Jan 23, 2017 at 01:16:40PM -0500, Johannes Weiner wrote: > Dirty pages can easily reach the end of the LRU while there are still > clean pages to reclaim around. Don't let kswapd write them back just > because there are a lot of them. It costs more CPU to find the clean > pages, but that's

Re: [PATCH 4/5] mm: vmscan: only write dirty pages that the scanner has seen twice

2017-01-26 Thread Mel Gorman
On Mon, Jan 23, 2017 at 01:16:40PM -0500, Johannes Weiner wrote: > Dirty pages can easily reach the end of the LRU while there are still > clean pages to reclaim around. Don't let kswapd write them back just > because there are a lot of them. It costs more CPU to find the clean > pages, but that's

Re: [PATCH 4/5] mm: vmscan: only write dirty pages that the scanner has seen twice

2017-01-25 Thread Minchan Kim
On Mon, Jan 23, 2017 at 01:16:40PM -0500, Johannes Weiner wrote: > Dirty pages can easily reach the end of the LRU while there are still > clean pages to reclaim around. Don't let kswapd write them back just > because there are a lot of them. It costs more CPU to find the clean > pages, but that's

Re: [PATCH 4/5] mm: vmscan: only write dirty pages that the scanner has seen twice

2017-01-25 Thread Minchan Kim
On Mon, Jan 23, 2017 at 01:16:40PM -0500, Johannes Weiner wrote: > Dirty pages can easily reach the end of the LRU while there are still > clean pages to reclaim around. Don't let kswapd write them back just > because there are a lot of them. It costs more CPU to find the clean > pages, but that's

[PATCH 4/5] mm: vmscan: only write dirty pages that the scanner has seen twice

2017-01-23 Thread Johannes Weiner
Dirty pages can easily reach the end of the LRU while there are still clean pages to reclaim around. Don't let kswapd write them back just because there are a lot of them. It costs more CPU to find the clean pages, but that's almost certainly better than to disrupt writeback from the flushers with

[PATCH 4/5] mm: vmscan: only write dirty pages that the scanner has seen twice

2017-01-23 Thread Johannes Weiner
Dirty pages can easily reach the end of the LRU while there are still clean pages to reclaim around. Don't let kswapd write them back just because there are a lot of them. It costs more CPU to find the clean pages, but that's almost certainly better than to disrupt writeback from the flushers with