From: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
To: Johannes Weiner <hannes@cmpxchg.org>
Cc: nishimura@mxp.nes.nec.co.jp,
KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>,
Minchan Kim <minchan.kim@gmail.com>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
Andrew Morton <akpm@linux-foundation.org>,
"Rafael J. Wysocki" <rjw@sisk.pl>, Rik van Riel <riel@redhat.com>,
Balbir Singh <balbir@in.ibm.com>
Subject: Re: [PATCH] vmscan: memcg needs may_swap (Re: [patch] vmscan: rename sc.may_swap to may_unmap)
Date: Wed, 1 Apr 2009 14:08:28 +0900 [thread overview]
Message-ID: <20090401140828.755f87aa.nishimura@mxp.nes.nec.co.jp> (raw)
In-Reply-To: <20090401040951.GA1548@cmpxchg.org>
On Wed, 1 Apr 2009 06:09:51 +0200, Johannes Weiner <hannes@cmpxchg.org> wrote:
> On Tue, Mar 31, 2009 at 10:48:32AM +0900, KOSAKI Motohiro wrote:
> > > > Sorry for too late response.
> > > > I don't know memcg well.
> > > >
> > > > The memcg managed to use may_swap well with global page reclaim until now.
> > > > I think that was because may_swap can represent both meaning.
> > > > Do we need each variables really ?
> > > >
> > > > How about using union variable ?
> > >
> > > or Just removing one of them ?
> >
> > I hope all may_unmap user convert to using may_swap.
> > may_swap is more efficient and cleaner meaning.
>
> How about making may_swap mean the following:
>
> @@ -642,6 +639,8 @@ static unsigned long shrink_page_list(st
> * Try to allocate it some swap space here.
> */
> if (PageAnon(page) && !PageSwapCache(page)) {
> + if (!sc->map_swap)
> + goto keep_locked;
> if (!(sc->gfp_mask & __GFP_IO))
> goto keep_locked;
> if (!add_to_swap(page))
>
but it doesn't work for shmem/tmpfs, does it?
So, I did in my first patch like:
@@ -616,6 +619,11 @@ static unsigned long shrink_page_list(struct list_head *page_list,
if (!sc->may_unmap && page_mapped(page))
goto keep_locked;
+ if (!sc->may_swap && PageSwapBacked(page)
+ /* SwapCache uses 'swap' already */
+ && !PageSwapCache(page))
+ goto keep_locked;
+
/* Double the slab pressure for mapped and swapcache pages */
if (page_mapped(page) || PageSwapCache(page))
sc->nr_scanned++;
> try_to_free_pages() always sets it.
>
> try_to_free_mem_cgroup_pages() sets it depending on whether it really
> wants swapping, and only swapping, right?
right.
> But the above would still reclaim already swapped anon pages
then, it would be better to add a check at shrink_page_list anyway..
Kosaki-san, what do you think?
Thanks,
Daisuke Nishimura.
> and I don't know the memory
> controller.
>
> balance_pgdat() always sets it.
>
> __zone_reclaim() sets it depending on zone_reclaim_mode. The
> RECLAIM_SWAP bit of this field and its documentation in
> Documentation/sysctl/vm.txt suggests it also really only means swap.
>
> shrink_all_memory() would be the sole user of may_unmap because it
> really wants to eat cache first. But this could be figured out on a
> different occasion.
>
> Hannes
next prev parent reply other threads:[~2009-04-01 5:22 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-02-06 3:11 [PATCH 0/3] [PATCH 0/3] swsusp: shrink file cache first Johannes Weiner
2009-02-06 3:11 ` [PATCH 1/3] swsusp: clean up shrink_all_zones() Johannes Weiner
2009-02-06 3:20 ` KOSAKI Motohiro
2009-02-06 3:11 ` [PATCH 2/3] swsusp: dont fiddle with swappiness Johannes Weiner
2009-02-06 3:21 ` KOSAKI Motohiro
2009-02-06 3:11 ` [PATCH 3/3][RFC] swsusp: shrink file cache first Johannes Weiner
2009-02-06 3:39 ` KOSAKI Motohiro
2009-02-06 4:49 ` Johannes Weiner
2009-02-06 5:59 ` KOSAKI Motohiro
2009-02-06 12:24 ` Johannes Weiner
2009-02-06 13:35 ` MinChan Kim
2009-02-06 17:15 ` MinChan Kim
2009-02-06 23:37 ` Johannes Weiner
2009-02-09 19:43 ` [patch] vmscan: rename sc.may_swap to may_unmap Johannes Weiner
2009-02-09 23:02 ` MinChan Kim
2009-02-10 10:00 ` KOSAKI Motohiro
2009-03-27 6:19 ` [PATCH] vmscan: memcg needs may_swap (Re: [patch] vmscan: rename sc.may_swap to may_unmap) Daisuke Nishimura
2009-03-27 6:30 ` KAMEZAWA Hiroyuki
2009-03-29 23:45 ` KOSAKI Motohiro
2009-03-31 0:18 ` Daisuke Nishimura
2009-03-31 1:26 ` Minchan Kim
2009-03-31 1:42 ` KAMEZAWA Hiroyuki
2009-03-31 1:48 ` KOSAKI Motohiro
2009-04-01 4:09 ` Johannes Weiner
2009-04-01 5:08 ` Daisuke Nishimura [this message]
2009-04-01 9:04 ` KAMEZAWA Hiroyuki
2009-04-01 9:11 ` KOSAKI Motohiro
2009-04-01 9:49 ` Johannes Weiner
2009-04-01 9:55 ` KOSAKI Motohiro
2009-04-01 16:03 ` Johannes Weiner
2009-03-31 1:52 ` Daisuke Nishimura
2009-02-06 21:00 ` [PATCH 3/3][RFC] swsusp: shrink file cache first Andrew Morton
2009-02-06 23:27 ` Johannes Weiner
2009-02-07 17:23 ` Rafael J. Wysocki
2009-02-08 20:56 ` Johannes Weiner
2009-02-07 4:41 ` Nigel Cunningham
2009-02-07 16:51 ` KOSAKI Motohiro
2009-02-07 21:20 ` Nigel Cunningham
2009-02-27 13:27 ` Pavel Machek
2009-03-01 10:37 ` KOSAKI Motohiro
2009-02-06 8:03 ` MinChan Kim
2009-02-06 10:06 ` MinChan Kim
2009-02-06 11:50 ` Johannes Weiner
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