On Fri, Feb 28, 2020 at 06:56:11PM +0900, Joonsoo Kim wrote: > On Fri, Feb 28, 2020 at 05:17:00PM +0800, Aaron Lu wrote: > > I think LKP robot has captured these two metrics but the report didn't > > show them, which means the number is about the same with or without > > patch #1. > > robot showed these two metrics. See below. > > 50190319 ± 31% -35.7% 32291856 ± 14% proc-vmstat.pswpin > 56429784 ± 21% -42.6% 32386842 ± 14% proc-vmstat.pswpout > > pswpin/out are improved. Oh yes, I checked the vmstat part, while I should check proc-vmstat part...Sorry for missing this. > > > > with patch #1. With large inactive list, we can easily find the > > > frequently referenced page and it would result in less swap in/out. > > > > But with small inactive list, the pages that would be on inactive list > > will stay on active list? I think the larger inactive list is mainly > > used to give the anon page a chance to be promoted to active list now > > that anon pages land on inactive list first, but on reclaim, I don't see > > how a larger inactive list can cause fewer swap outs. > > Point is that larger inactive LRU helps to find hot pages and these > hot pages leads to more cache hits. > > When a cache hit happens, no swap outs happens. But, if a cache miss > happens, a new page is added to the LRU and then it causes the reclaim > and swap out. OK, I think I start to get your point. Your explanation makes sense. > > Forgive me for my curiosity and feel free to ignore my question as I > > don't want to waste your time on this. Your patchset looks a worthwhile > > thing to do, it's just the robot's report on patch1 seems er... > > I appreciate your attention. Feel free to ask. :) Thanks a lot for your patience and nice explanation :-)
