On Mon 12-09-11 12:57:19, Johannes Weiner wrote: > The traditional zone reclaim code is scanning the per-zone LRU lists > during direct reclaim and kswapd, and the per-zone per-memory cgroup > LRU lists when reclaiming on behalf of a memory cgroup limit. > > Subsequent patches will convert the traditional reclaim code to > reclaim exclusively from the per-memory cgroup LRU lists. As a > result, using the predicate for which LRU list is scanned will no > longer be appropriate to tell global reclaim from limit reclaim. > > This patch adds a global_reclaim() predicate to tell direct/kswapd > reclaim from memory cgroup limit reclaim and substitutes it in all > places where currently scanning_global_lru() is used for that. I am wondering about vmscan_swappiness. Shouldn't it use global_reclaim instead? Other than that it looks good to me. Reviewed-by: Michal Hocko <mhocko@xxxxxxx> > > Signed-off-by: Johannes Weiner <jweiner@xxxxxxxxxx> > --- > mm/vmscan.c | 60 +++++++++++++++++++++++++++++++++++----------------------- > 1 files changed, 36 insertions(+), 24 deletions(-) > > diff --git a/mm/vmscan.c b/mm/vmscan.c > index 7502726..354f125 100644 > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -153,9 +153,25 @@ static LIST_HEAD(shrinker_list); > static DECLARE_RWSEM(shrinker_rwsem); > > #ifdef CONFIG_CGROUP_MEM_RES_CTLR > -#define scanning_global_lru(sc) (!(sc)->mem_cgroup) > +static bool global_reclaim(struct scan_control *sc) > +{ > + return !sc->mem_cgroup; > +} > + > +static bool scanning_global_lru(struct scan_control *sc) > +{ > + return !sc->mem_cgroup; > +} > #else > -#define scanning_global_lru(sc) (1) > +static bool global_reclaim(struct scan_control *sc) > +{ > + return true; > +} > + > +static bool scanning_global_lru(struct scan_control *sc) > +{ > + return true; > +} > #endif > > static struct zone_reclaim_stat *get_reclaim_stat(struct zone *zone, > @@ -1011,7 +1027,7 @@ keep_lumpy: > * back off and wait for congestion to clear because further reclaim > * will encounter the same problem > */ > - if (nr_dirty && nr_dirty == nr_congested && scanning_global_lru(sc)) > + if (nr_dirty && nr_dirty == nr_congested && global_reclaim(sc)) > zone_set_flag(zone, ZONE_CONGESTED); > > free_page_list(&free_pages); > @@ -1330,7 +1346,7 @@ static int too_many_isolated(struct zone *zone, int file, > if (current_is_kswapd()) > return 0; > > - if (!scanning_global_lru(sc)) > + if (!global_reclaim(sc)) > return 0; > > if (file) { > @@ -1508,6 +1524,12 @@ shrink_inactive_list(unsigned long nr_to_scan, struct zone *zone, > if (scanning_global_lru(sc)) { > nr_taken = isolate_pages_global(nr_to_scan, &page_list, > &nr_scanned, sc->order, reclaim_mode, zone, 0, file); > + } else { > + nr_taken = mem_cgroup_isolate_pages(nr_to_scan, &page_list, > + &nr_scanned, sc->order, reclaim_mode, zone, > + sc->mem_cgroup, 0, file); > + } > + if (global_reclaim(sc)) { > zone->pages_scanned += nr_scanned; > if (current_is_kswapd()) > __count_zone_vm_events(PGSCAN_KSWAPD, zone, > @@ -1515,14 +1537,6 @@ shrink_inactive_list(unsigned long nr_to_scan, struct zone *zone, > else > __count_zone_vm_events(PGSCAN_DIRECT, zone, > nr_scanned); > - } else { > - nr_taken = mem_cgroup_isolate_pages(nr_to_scan, &page_list, > - &nr_scanned, sc->order, reclaim_mode, zone, > - sc->mem_cgroup, 0, file); > - /* > - * mem_cgroup_isolate_pages() keeps track of > - * scanned pages on its own. > - */ > } > > if (nr_taken == 0) { > @@ -1647,18 +1661,16 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone, > &pgscanned, sc->order, > reclaim_mode, zone, > 1, file); > - zone->pages_scanned += pgscanned; > } else { > nr_taken = mem_cgroup_isolate_pages(nr_pages, &l_hold, > &pgscanned, sc->order, > reclaim_mode, zone, > sc->mem_cgroup, 1, file); > - /* > - * mem_cgroup_isolate_pages() keeps track of > - * scanned pages on its own. > - */ > } > > + if (global_reclaim(sc)) > + zone->pages_scanned += pgscanned; > + > reclaim_stat->recent_scanned[file] += nr_taken; > > __count_zone_vm_events(PGREFILL, zone, pgscanned); > @@ -1863,9 +1875,9 @@ static void get_scan_count(struct zone *zone, struct scan_control *sc, > * latencies, so it's better to scan a minimum amount there as > * well. > */ > - if (scanning_global_lru(sc) && current_is_kswapd()) > + if (current_is_kswapd()) > force_scan = true; > - if (!scanning_global_lru(sc)) > + if (!global_reclaim(sc)) > force_scan = true; > > /* If we have no swap space, do not bother scanning anon pages. */ > @@ -1882,7 +1894,7 @@ static void get_scan_count(struct zone *zone, struct scan_control *sc, > file = zone_nr_lru_pages(zone, sc, LRU_ACTIVE_FILE) + > zone_nr_lru_pages(zone, sc, LRU_INACTIVE_FILE); > > - if (scanning_global_lru(sc)) { > + if (global_reclaim(sc)) { > free = zone_page_state(zone, NR_FREE_PAGES); > /* If we have very few page cache pages, > force-scan anon pages. */ > @@ -2109,7 +2121,7 @@ static void shrink_zones(int priority, struct zonelist *zonelist, > * Take care memory controller reclaiming has small influence > * to global LRU. > */ > - if (scanning_global_lru(sc)) { > + if (global_reclaim(sc)) { > if (!cpuset_zone_allowed_hardwall(zone, GFP_KERNEL)) > continue; > if (zone->all_unreclaimable && priority != DEF_PRIORITY) > @@ -2188,7 +2200,7 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist, > get_mems_allowed(); > delayacct_freepages_start(); > > - if (scanning_global_lru(sc)) > + if (global_reclaim(sc)) > count_vm_event(ALLOCSTALL); > > for (priority = DEF_PRIORITY; priority >= 0; priority--) { > @@ -2200,7 +2212,7 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist, > * Don't shrink slabs when reclaiming memory from > * over limit cgroups > */ > - if (scanning_global_lru(sc)) { > + if (global_reclaim(sc)) { > unsigned long lru_pages = 0; > for_each_zone_zonelist(zone, z, zonelist, > gfp_zone(sc->gfp_mask)) { > @@ -2261,7 +2273,7 @@ out: > return 0; > > /* top priority shrink_zones still had more to do? don't OOM, then */ > - if (scanning_global_lru(sc) && !all_unreclaimable(zonelist, sc)) > + if (global_reclaim(sc) && !all_unreclaimable(zonelist, sc)) > return 1; > > return 0; > -- > 1.7.6 > -- Michal Hocko SUSE Labs SUSE LINUX s.r.o. 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