On Fri, 24 Jul 2009 14:44:16 +0900 (JST) Ryo Tsuruta <ryov@xxxxxxxxxxxxx> wrote: good solution to resolve such problem. > > > My point is "don't allow anyone to use bandwidth of others." > > Considering job isolation, a thread who requests swap-out should be charg= > > ed > > against bandwidth. > > From another perspective, the swap-out is caused since the buggy > process uses a large amount of memory, so it can be considered as > the bandwidth of logging process is used due to the buggy process. > > Please consider the following case. If a thread who requests swap-out > is charged, the thread is charged other threads' I/O. > > (1) -------- (2) > Process A | | Process B > mmaps a large area in --> | memory | <-- tries to allocate a page. > the memory and writes | | > data to there. -------- (3) > | To get a free page, > | the data written by Proc.A > | is written out to the disk. > V The I/O is done by using > --------- Proc.B's bandwidth. > | disk | > --------- > > Thus I think that page owners should be charged against bandwidth. > Ok, no good way. yours is wrong, mine is wrong, too. plz find 3rd way, reasonable. Below is brief thinking. "Why process A should be charged to I/O when it just maps anon memory ?" I can't answer this. Even in yorr case, Process B requests memory and get penalty. It's very natural, I think. In usual case, - if process A maps ANON, there will be no I/O. - if process A maps FILE, it will be charged to process A. ok ? Under memory pressure, - if process A maps ANON, swap I/O should be charged to process B. - if process A maps FILE, I/O should be charged to process A. maybe. Anyway, there will be ineraction with dirty_ratio of memcg (not implemeted yet) and _Owner should be charged_ issue will be handled in this dirty_ratio layer. More consideration is necessary, I think. Bye, -Kame -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
