On Thu, Dec 13, 2018 at 03:57:25PM +0800, guangrong.xiao@xxxxxxxxx wrote: > From: Xiao Guangrong <xiaoguangrong@xxxxxxxxxxx> > > Currently we have two behaviors if all threads are busy to do compression, > the main thread mush wait one of them becoming free if @compress-wait-thread > set to on or the main thread can directly return without wait and post > the page out as normal one > > Both of them have its profits and short-comes, however, if the bandwidth is > not limited extremely so that compression can not use out all of it bandwidth, > at the same time, the migration process is easily throttled if we posted too > may pages as normal pages. None of them can work properly under this case > > In order to use the bandwidth more effectively, we introduce the third > behavior, compress-wait-thread-adaptive, which make the main thread wait > if there is no bandwidth left or let the page go out as normal page if there > has enough bandwidth to make sure the migration process will not be > throttled > > Another patch introduces a new statistic, pages-per-second, as bandwidth > or mbps is not enough to measure the performance of posting pages out as > we have compression, xbzrle, which can significantly reduce the amount of > the data size, instead, pages-per-second if the one we want > > Performance data > ================ > We have limited the bandwidth to 300 > > Used Bandwidth Pages-per-Second > compress-wait-thread = on 951.66 mbps 131784 > > compress-wait-thread = off 2491.74 mbps 93495 > compress-wait-thread-adaptive 1982.94 mbps 162529 > = on Sounds reasonable to me, though it looks like there're only three options: on, off, adaptive. Should we squash the two parameters? Thanks, -- Peter Xu
