On Thu 04-07-19 17:47:16, Kuo-Hsin Yang wrote: > On Wed, Jul 03, 2019 at 04:30:57PM +0200, Michal Hocko wrote: > > > > How does the reclaim behave with workloads with file backed data set > > not fitting into the memory? Aren't we going to to swap a lot - > > something that the heuristic is protecting from? > > > > In common case, most of the pages in a large file backed data set are > non-executable. When there are a lot of non-executable file pages, > usually more file pages are scanned because of the recent_scanned / > recent_rotated ratio. > > I modified the test program to set the accessed sizes of the executable > and non-executable file pages respectively. The test program runs on 2GB > RAM VM with kernel 5.2.0-rc7 and this patch, allocates 2000 MB anonymous > memory, then accesses 100 MB executable file pages and 2100 MB > non-executable file pages for 10 times. The test also prints the file > and anonymous page sizes in kB from /proc/meminfo. There are not too > many swaps in this test case. I got similar test result without this > patch. Could you record swap out stats please? Also what happens if you have multiple readers? Thanks! -- Michal Hocko SUSE Labs
