On Fri, Apr 16, 2010 at 08:19:00PM +0900, KOSAKI Motohiro wrote: > > When shrink_inactive_list() isolates pages, it updates a number of > > counters using temporary variables to gather them. These consume stack > > and it's in the main path that calls ->writepage(). This patch moves the > > accounting updates outside of the main path to reduce stack usage. > > > > Signed-off-by: Mel Gorman <mel@xxxxxxxxx> > > --- > > mm/vmscan.c | 63 +++++++++++++++++++++++++++++++++++----------------------- > > 1 files changed, 38 insertions(+), 25 deletions(-) > > > > diff --git a/mm/vmscan.c b/mm/vmscan.c > > index 2c22c83..4225319 100644 > > --- a/mm/vmscan.c > > +++ b/mm/vmscan.c > > @@ -1061,7 +1061,8 @@ static unsigned long clear_active_flags(struct list_head *page_list, > > ClearPageActive(page); > > nr_active++; > > } > > - count[lru]++; > > + if (count) > > + count[lru]++; > > } > > > > return nr_active; > > @@ -1141,12 +1142,13 @@ static int too_many_isolated(struct zone *zone, int file, > > * TODO: Try merging with migrations version of putback_lru_pages > > */ > > static noinline void putback_lru_pages(struct zone *zone, > > - struct zone_reclaim_stat *reclaim_stat, > > + struct scan_control *sc, > > unsigned long nr_anon, unsigned long nr_file, > > struct list_head *page_list) > > { > > struct page *page; > > struct pagevec pvec; > > + struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(zone, sc); > > Seems unrelated change here. > Otherwise looks good. > It was needed somewhat otherwise the split in accounting looked odd. It could be done as two patches but it felt trickier to review. > - kosaki > > > > pagevec_init(&pvec, 1); > > > > @@ -1185,6 +1187,37 @@ static noinline void putback_lru_pages(struct zone *zone, > > pagevec_release(&pvec); > > } > > > > +static noinline void update_isolated_counts(struct zone *zone, > > + struct scan_control *sc, > > + unsigned long *nr_anon, > > + unsigned long *nr_file, > > + struct list_head *isolated_list) > > +{ > > + unsigned long nr_active; > > + unsigned int count[NR_LRU_LISTS] = { 0, }; > > + struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(zone, sc); > > + > > + nr_active = clear_active_flags(isolated_list, count); > > + __count_vm_events(PGDEACTIVATE, nr_active); > > + > > + __mod_zone_page_state(zone, NR_ACTIVE_FILE, > > + -count[LRU_ACTIVE_FILE]); > > + __mod_zone_page_state(zone, NR_INACTIVE_FILE, > > + -count[LRU_INACTIVE_FILE]); > > + __mod_zone_page_state(zone, NR_ACTIVE_ANON, > > + -count[LRU_ACTIVE_ANON]); > > + __mod_zone_page_state(zone, NR_INACTIVE_ANON, > > + -count[LRU_INACTIVE_ANON]); > > + > > + *nr_anon = count[LRU_ACTIVE_ANON] + count[LRU_INACTIVE_ANON]; > > + *nr_file = count[LRU_ACTIVE_FILE] + count[LRU_INACTIVE_FILE]; > > + __mod_zone_page_state(zone, NR_ISOLATED_ANON, *nr_anon); > > + __mod_zone_page_state(zone, NR_ISOLATED_FILE, *nr_file); > > + > > + reclaim_stat->recent_scanned[0] += *nr_anon; > > + reclaim_stat->recent_scanned[1] += *nr_file; > > +} > > + > > /* > > * shrink_inactive_list() is a helper for shrink_zone(). It returns the number > > * of reclaimed pages > > @@ -1196,11 +1229,9 @@ static unsigned long shrink_inactive_list(unsigned long nr_to_scan, > > LIST_HEAD(page_list); > > unsigned long nr_scanned; > > unsigned long nr_reclaimed = 0; > > - struct zone_reclaim_stat *reclaim_stat = get_reclaim_stat(zone, sc); > > int lumpy_reclaim = 0; > > unsigned long nr_taken; > > unsigned long nr_active; > > - unsigned int count[NR_LRU_LISTS] = { 0, }; > > unsigned long nr_anon; > > unsigned long nr_file; > > > > @@ -1244,25 +1275,7 @@ static unsigned long shrink_inactive_list(unsigned long nr_to_scan, > > return 0; > > } > > > > - nr_active = clear_active_flags(&page_list, count); > > - __count_vm_events(PGDEACTIVATE, nr_active); > > - > > - __mod_zone_page_state(zone, NR_ACTIVE_FILE, > > - -count[LRU_ACTIVE_FILE]); > > - __mod_zone_page_state(zone, NR_INACTIVE_FILE, > > - -count[LRU_INACTIVE_FILE]); > > - __mod_zone_page_state(zone, NR_ACTIVE_ANON, > > - -count[LRU_ACTIVE_ANON]); > > - __mod_zone_page_state(zone, NR_INACTIVE_ANON, > > - -count[LRU_INACTIVE_ANON]); > > - > > - nr_anon = count[LRU_ACTIVE_ANON] + count[LRU_INACTIVE_ANON]; > > - nr_file = count[LRU_ACTIVE_FILE] + count[LRU_INACTIVE_FILE]; > > - __mod_zone_page_state(zone, NR_ISOLATED_ANON, nr_anon); > > - __mod_zone_page_state(zone, NR_ISOLATED_FILE, nr_file); > > - > > - reclaim_stat->recent_scanned[0] += nr_anon; > > - reclaim_stat->recent_scanned[1] += nr_file; > > + update_isolated_counts(zone, sc, &nr_anon, &nr_file, &page_list); > > > > spin_unlock_irq(&zone->lru_lock); > > > > @@ -1281,7 +1294,7 @@ static unsigned long shrink_inactive_list(unsigned long nr_to_scan, > > * The attempt at page out may have made some > > * of the pages active, mark them inactive again. > > */ > > - nr_active = clear_active_flags(&page_list, count); > > + nr_active = clear_active_flags(&page_list, NULL); > > count_vm_events(PGDEACTIVATE, nr_active); > > > > nr_reclaimed += shrink_page_list(&page_list, sc, > > @@ -1293,7 +1306,7 @@ static unsigned long shrink_inactive_list(unsigned long nr_to_scan, > > __count_vm_events(KSWAPD_STEAL, nr_reclaimed); > > __count_zone_vm_events(PGSTEAL, zone, nr_reclaimed); > > > > - putback_lru_pages(zone, reclaim_stat, nr_anon, nr_file, &page_list); > > + putback_lru_pages(zone, sc, nr_anon, nr_file, &page_list); > > return nr_reclaimed; > > } > > > > -- > > 1.6.5 > > > > > -- Mel Gorman Part-time Phd Student Linux Technology Center University of Limerick IBM Dublin Software Lab -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html