Messages in this thread | | | Date | Thu, 12 Mar 2009 12:51:24 +0900 | From | KAMEZAWA Hiroyuki <> | Subject | Re: [BUGFIX][PATCH 1/5] memcg use correct scan number at reclaim |
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On Thu, 12 Mar 2009 09:19:18 +0530 Balbir Singh <balbir@linux.vnet.ibm.com> wrote:
> * KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> [2009-03-12 09:55:16]: > > > Andrew, this [1/5] is a bug fix, others are not. > > > > == > > From: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> > > > > Even when page reclaim is under mem_cgroup, # of scan page is determined by > > status of global LRU. Fix that. > > > > Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> > > Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> > > --- > > mm/vmscan.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > Index: mmotm-2.6.29-Mar10/mm/vmscan.c > > =================================================================== > > --- mmotm-2.6.29-Mar10.orig/mm/vmscan.c > > +++ mmotm-2.6.29-Mar10/mm/vmscan.c > > @@ -1470,7 +1470,7 @@ static void shrink_zone(int priority, st > > int file = is_file_lru(l); > > int scan; > > > > - scan = zone_page_state(zone, NR_LRU_BASE + l); > > + scan = zone_nr_pages(zone, sc, l); > > I have the exact same patch in my patch queue. BTW, mem_cgroup_zone_nr_pages is > buggy. We don't hold any sort of lock while extracting > MEM_CGROUP_ZSTAT (ideally we need zone->lru_lock). Without that how do > we guarantee that MEM_CGRUP_ZSTAT is not changing at the same time as > we are reading it? > Is it big problem ? We don't need very precise value and ZSTAT just have increment/decrement. So, I tend to ignore this small race. (and it's unsigned long, not long long.)
Thanks, -Kame
> > if (priority) { > > scan >>= priority; > > scan = (scan * percent[file]) / 100; > > > > > > -- > Balbir >
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