On Tue 06-08-19 20:00:24, Minchan Kim wrote: > On Tue, Aug 06, 2019 at 10:04:15AM +0200, Michal Hocko wrote: > > On Tue 06-08-19 15:05:47, kernel test robot wrote: > > > Greeting, > > > > > > FYI, we noticed a -4.1% regression of will-it-scale.per_process_ops due to commit: > > > > I have to confess I cannot make much sense from numbers because they > > seem to be too volatile and the main contributor doesn't stand up for > > me. Anyway, regressions on microbenchmarks like this are not all that > > surprising when a locking is slightly changed and the critical section > > made shorter. I have seen that in the past already. > > I guess if it's multi process workload. The patch will give more chance > to be scheduled out so TLB miss ratio would be bigger than old. > I see it's natural trade-off for latency vs. performance so only thing > I could think is just increase threshold from 32 to 64 or 128? This still feels like a magic number tunning, doesn't it? -- Michal Hocko SUSE Labs
