Acked-by: Ying Han <yinghan@xxxxxxxxxx> --Ying On Wed, Apr 27, 2011 at 2:14 AM, Minchan Kim <minchan.kim@xxxxxxxxx> wrote: > On Wed, Apr 27, 2011 at 5:48 PM, KAMEZAWA Hiroyuki > <kamezawa.hiroyu@xxxxxxxxxxxxxx> wrote: >> On Wed, 27 Apr 2011 17:48:18 +0900 >> Minchan Kim <minchan.kim@xxxxxxxxx> wrote: >> >>> On Wed, Apr 27, 2011 at 4:47 PM, KAMEZAWA Hiroyuki >>> <kamezawa.hiroyu@xxxxxxxxxxxxxx> wrote: >>> > At memory reclaim, we determine the number of pages to be scanned >>> > per zone as >>> > (anon + file) >> priority. >>> > Assume >>> > scan = (anon + file) >> priority. >>> > >>> > If scan < SWAP_CLUSTER_MAX, the scan will be skipped for this time >>> > and priority gets higher. This has some problems. >>> > >>> > 1. This increases priority as 1 without any scan. >>> > To do scan in this priority, amount of pages should be larger than 512M. >>> > If pages>>priority < SWAP_CLUSTER_MAX, it's recorded and scan will be >>> > batched, later. (But we lose 1 priority.) >>> > If memory size is below 16M, pages >> priority is 0 and no scan in >>> > DEF_PRIORITY forever. >>> > >>> > 2. If zone->all_unreclaimabe==true, it's scanned only when priority==0. >>> > So, x86's ZONE_DMA will never be recoverred until the user of pages >>> > frees memory by itself. >>> > >>> > 3. With memcg, the limit of memory can be small. When using small memcg, >>> > it gets priority < DEF_PRIORITY-2 very easily and need to call >>> > wait_iff_congested(). >>> > For doing scan before priorty=9, 64MB of memory should be used. >>> > >>> > Then, this patch tries to scan SWAP_CLUSTER_MAX of pages in force...when >>> > >>> > 1. the target is enough small. >>> > 2. it's kswapd or memcg reclaim. >>> > >>> > Then we can avoid rapid priority drop and may be able to recover >>> > all_unreclaimable in a small zones. And this patch removes nr_saved_scan. >>> > This will allow scanning in this priority even when pages >> priority >>> > is very small. >>> > >>> > Changelog v2->v3 >>> > - removed nr_saved_scan completely. >>> > >>> > Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> >>> Reviewed-by: Minchan Kim <minchan.kim@xxxxxxxxx> >>> >>> The patch looks good to me but I have a nitpick about just coding style. >>> How about this? I think below looks better but it's just my private >>> opinion and I can't insist on my style. If you don't mind it, ignore. >>> >> >> I did this at the 1st try and got bug.....a variable 'file' here is >> reused and now broken. Renaming it with new variable will be ok, but it > > Right you are. I missed that. :) > Thanks. > > > -- > 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href