On Wed, 18 Jan 2012 09:17:17 -0500 Rik van Riel <riel@xxxxxxxxxx> wrote: > On 01/17/2012 07:18 PM, KAMEZAWA Hiroyuki wrote: > > On Wed, 18 Jan 2012 08:08:01 +0900 > > Minchan Kim<minchan@xxxxxxxxxx> wrote: > > > >>>>> 2. can't we measure page-in/page-out distance by recording something ? > >>>> > >>>> I can't understand your point. What's relation does it with swapout prevent? > >>>> > >>> > >>> If distance between pageout -> pagein is short, it means thrashing. > >>> For example, recoding the timestamp when the page(mapping, index) was > >>> paged-out, and check it at page-in. > >> > >> Our goal is prevent swapout. When we found thrashing, it's too late. > > > > If you want to prevent swap-out, don't swapon any. That's all. > > Then, you can check the number of FILE_CACHE and have threshold. > > I think you are getting hung up on a word here. > > As I understand it, the goal is to push out the point where > we start doing heavier swap IO, allowing us to overcommit > memory more heavily before things start really slowing down. > Yes. Hmm, considering that the issue is slow down, time values as - 'cpu time used for memory reclaim' - 'latency of page allocation' - 'application execution speed' ? may be a better score to see rather than just seeing lru's stat. Thanks, -Kame -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>