Messages in this thread |  | | | From | KOSAKI Motohiro <> | | Subject | Re: [PATCH 6/8] Stop reclaim quickly when the task reclaimed enough lots pages | | Date | Tue, 15 Dec 2009 09:35:41 +0900 (JST) |
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> On Mon, 14 Dec 2009 21:31:36 +0900 (JST) > KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> wrote: > > > > > From latency view, There isn't any reason shrink_zones() continue to > > reclaim another zone's page if the task reclaimed enough lots pages. > > > > Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> > > --- > > mm/vmscan.c | 16 ++++++++++++---- > > 1 files changed, 12 insertions(+), 4 deletions(-) > > > > diff --git a/mm/vmscan.c b/mm/vmscan.c > > index 0880668..bf229d3 100644 > > --- a/mm/vmscan.c > > +++ b/mm/vmscan.c > > @@ -1654,7 +1654,7 @@ static void shrink_zone_end(struct zone *zone, struct scan_control *sc) > > /* > > * This is a basic per-zone page freer. Used by both kswapd and direct reclaim. > > */ > > -static void shrink_zone(int priority, struct zone *zone, > > +static int shrink_zone(int priority, struct zone *zone, > > struct scan_control *sc) > > { > > unsigned long nr[NR_LRU_LISTS]; > > @@ -1669,7 +1669,7 @@ static void shrink_zone(int priority, struct zone *zone, > > > > ret = shrink_zone_begin(zone, sc); > > if (ret) > > - return; > > + return ret; > > > > /* If we have no swap space, do not bother scanning anon pages. */ > > if (!sc->may_swap || (nr_swap_pages <= 0)) { > > @@ -1692,6 +1692,7 @@ static void shrink_zone(int priority, struct zone *zone, > > &reclaim_stat->nr_saved_scan[l]); > > } > > > > + ret = 0; > > while (nr[LRU_INACTIVE_ANON] || nr[LRU_ACTIVE_FILE] || > > nr[LRU_INACTIVE_FILE]) { > > for_each_evictable_lru(l) { > > @@ -1712,8 +1713,10 @@ static void shrink_zone(int priority, struct zone *zone, > > * with multiple processes reclaiming pages, the total > > * freeing target can get unreasonably large. > > */ > > - if (nr_reclaimed >= nr_to_reclaim && priority < DEF_PRIORITY) > > + if (nr_reclaimed >= nr_to_reclaim && priority < DEF_PRIORITY) { > > + ret = -ERESTARTSYS; > > Just nitpick. > > shrink_zone's return value is matter? > shrink_zones never handle that.
shrink_zones() stop vmscan quickly if ret isn't !0. if we already scanned rather than nr_to_reclaim, we can stop vmscan.
> As a matter of fact, I am worried about this patch. > > My opinion is we put aside this patch until we can solve Larry's problem. > We could apply this patch in future. > > I don't want to see the side effect while we focus Larry's problem. > But If you mind my suggestion, I also will not bother you by this nitpick. > > Thanks for great cleanup and improving VM, Kosaki. :)
I agree with Larry's issue is highest priority.
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