On Sat, Jan 23, 2021 at 4:29 AM Zbigniew Jędrzejewski-Szmek <zbyszek@xxxxxxxxx> wrote: > > (One possible direction: one thing I want to explore next is using zram > or zwap based on whether the machine has a physical swap device. Maybe > such a language would be useful then — with additional variables > specifying e.g. the physical swap size…) What about setting vm.swappiness = 120? When set to 100, the bias for reclaiming anonymous pages and file pages is about equal. Setting it lower is predicated on (a) older kernels and (b) spinning drives where the cost for page out and page in is higher than dropping a file page and only reading it back in. With zram based swap, eviction and reclaim of anon pages is unquestionably a lot cheaper now, and even cheaper than the cost of reading in a file page. I'm even thinking it could be pushed higher than 120. I don't think there's a way to make this smart enough to scale this to the swap backing storage performance, which is what we really want. Hence 120 is a compromise in case there's also disk based swap. A down the road enhancement might be, if no disk based swap is detected, push this to 190. This would also allow some time to get some feedback with it set to 120 before pushing harder. -- Chris Murphy _______________________________________________ devel mailing list -- devel@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe send an email to devel-leave@xxxxxxxxxxxxxxxxxxxxxxx Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/devel@xxxxxxxxxxxxxxxxxxxxxxx
