On Thu, 10 Nov 2011 17:06:28 +0100 Johannes Weiner <jweiner@xxxxxxxxxx> wrote: > On Mon, Nov 07, 2011 at 11:34:17AM +0900, KAMEZAWA Hiroyuki wrote: > > On Wed, 2 Nov 2011 17:32:13 +0100 > > Johannes Weiner <jweiner@xxxxxxxxxx> wrote: > > > > > Each page that is scanned but put back to the inactive list is counted > > > as a successful reclaim, which tips the balance between file and anon > > > lists more towards the cycling list. > > > > > > This does - in my opinion - not make too much sense, but at the same > > > time it was not much of a problem, as the conditions that lead to an > > > inactive list cycle were mostly temporary - locked page, concurrent > > > page table changes, backing device congested - or at least limited to > > > a single reclaimer that was not allowed to unmap or meddle with IO. > > > More important than being moderately rare, those conditions should > > > apply to both anon and mapped file pages equally and balance out in > > > the end. > > > > > > Recently, we started cycling file pages in particular on the inactive > > > list much more aggressively, for used-once detection of mapped pages, > > > and when avoiding writeback from direct reclaim. > > > > > > Those rotated pages do not exactly speak for the reclaimability of the > > > list they sit on and we risk putting immense pressure on file list for > > > no good reason. > > > > > > Instead, count each page not reclaimed and put back to any list, > > > active or inactive, as rotated, so they are neutral with respect to > > > the scan/rotate ratio of the list class, as they should be. > > > > > > Signed-off-by: Johannes Weiner <jweiner@xxxxxxxxxx> > > > > I think this makes sense. > > > > Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx> > > > > I wonder it may be better to have victim list for written-backed pages.. > > Do you mean an extra LRU list that holds dirty pages? an extra LRU for pages PG_reclaim ? 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>