On Mon, Jul 26, 2010 at 12:37:09PM +0800, Wu Fengguang wrote: > On Mon, Jul 26, 2010 at 12:11:59PM +0800, Minchan Kim wrote: > > On Mon, Jul 26, 2010 at 12:27 PM, Wu Fengguang <fengguang.wu@xxxxxxxxx> wrote: > > > On Sun, Jul 25, 2010 at 08:03:45PM +0800, Minchan Kim wrote: > > >> On Sun, Jul 25, 2010 at 07:43:20PM +0900, KOSAKI Motohiro wrote: > > >> > Hi > > >> > > > >> > sorry for the delay. > > >> > > > >> > > Will you be picking it up or should I? The changelog should be more or less > > >> > > the same as yours and consider it > > >> > > > > >> > > Signed-off-by: Mel Gorman <mel@xxxxxxxxx> > > >> > > > > >> > > It'd be nice if the original tester is still knocking around and willing > > >> > > to confirm the patch resolves his/her problem. I am running this patch on > > >> > > my desktop at the moment and it does feel a little smoother but it might be > > >> > > my imagination. I had trouble with odd stalls that I never pinned down and > > >> > > was attributing to the machine being commonly heavily loaded but I haven't > > >> > > noticed them today. > > >> > > > > >> > > It also needs an Acked-by or Reviewed-by from Kosaki Motohiro as it alters > > >> > > logic he introduced in commit [78dc583: vmscan: low order lumpy reclaim also > > >> > > should use PAGEOUT_IO_SYNC] > > >> > > > >> > My reviewing doesn't found any bug. however I think original thread have too many guess > > >> > and we need to know reproduce way and confirm it. > > >> > > > >> > At least, we need three confirms. > > >> > o original issue is still there? > > >> > o DEF_PRIORITY/3 is best value? > > >> > > >> I agree. Wu, how do you determine DEF_PRIORITY/3 of LRU? > > >> I guess system has 512M and 22M writeback pages. > > >> So you may determine it for skipping max 32M writeback pages. > > >> Is right? > > > > > > For 512M mem, DEF_PRIORITY/3 means 32M dirty _or_ writeback pages. > > > Because shrink_inactive_list() first calls > > > shrink_page_list(PAGEOUT_IO_ASYNC) then optionally > > > shrink_page_list(PAGEOUT_IO_SYNC), so dirty pages will first be > > > converted to writeback pages and then optionally be waited on. > > > > > > The dirty/writeback pages may go up to 512M*20% = 100M. So 32M looks > > > a reasonable value. > > > > Why do you think it's a reasonable value? > > I mean why isn't it good 12.5% or 3.125%? Why do you select 6.25%? > > I am not against you. Just out of curiosity and requires more explanation. > > It might be thing _only I_ don't know. :( > > It's more or less random selected. I'm also OK with 3.125%. It's an > threshold to turn on some _last resort_ mechanism, so don't need to be > optimal.. Okay. Why I had a question is that I don't want to add new magic value in VM without detailed comment. While I review the source code, I always suffer form it. :( Now we have a great tool called 'git'. Please write down why we select that number detaily when we add new magic value. :) Thanks, Wu. -- Kind regards, Minchan Kim -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>