在 2020/11/21 上午7:19, Andrew Morton 写道: > On Fri, 20 Nov 2020 16:27:27 +0800 Alex Shi <alex.shi@xxxxxxxxxxxxxxxxx> wrote: > >> The current relock logical will change lru_lock when found a new >> lruvec, so if 2 memcgs are reading file or alloc page at same time, >> they could hold the lru_lock alternately, and wait for each other for >> fairness attribute of ticket spin lock. >> >> This patch will sort that all lru_locks and only hold them once in >> above scenario. That could reduce fairness waiting for lock reget. >> Than, vm-scalability/case-lru-file-readtwice could get ~5% performance >> gain on my 2P*20core*HT machine. > > But what happens when all or most of the pages belong to the same > lruvec? This sounds like the common case - won't it suffer? > Hi Andrew, My testing show no regression on this situation, like original centos7, The most spending time is on lru_lock for lru sensitive case. Thanks Alex
