From 9e3b2f8cd340e13353a44c9a34caef2848131ed7 Mon Sep 17 00:00:00 2001 From: Konstantin Khlebnikov Date: Tue, 29 May 2012 15:06:57 -0700 Subject: [PATCH] mm/vmscan: store "priority" in struct scan_control In memory reclaim some function have too many arguments - "priority" is one of them. It can be stored in struct scan_control - we construct them on the same level. Instead of an open coded loop we set the initial sc.priority, and do_try_to_free_pages() decreases it down to zero. Signed-off-by: Konstantin Khlebnikov Cc: Mel Gorman Cc: KAMEZAWA Hiroyuki Acked-by: Hugh Dickins Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/vmscan.c | 117 +++++++++++++++++++++++++++++++----------------------------- 1 file changed, 61 insertions(+), 56 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index 0e2131d..77905eb 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -78,6 +78,9 @@ struct scan_control { int order; + /* Scan (total_size >> priority) pages at once */ + int priority; + /* * The memory cgroup that hit its limit and as a result is the * primary target of this reclaim invocation. @@ -687,7 +690,6 @@ static enum page_references page_check_references(struct page *page, static unsigned long shrink_page_list(struct list_head *page_list, struct mem_cgroup_zone *mz, struct scan_control *sc, - int priority, unsigned long *ret_nr_dirty, unsigned long *ret_nr_writeback) { @@ -790,7 +792,8 @@ static unsigned long shrink_page_list(struct list_head *page_list, * unless under significant pressure. */ if (page_is_file_cache(page) && - (!current_is_kswapd() || priority >= DEF_PRIORITY - 2)) { + (!current_is_kswapd() || + sc->priority >= DEF_PRIORITY - 2)) { /* * Immediately reclaim when written back. * Similar in principal to deactivate_page() @@ -1257,7 +1260,7 @@ update_isolated_counts(struct mem_cgroup_zone *mz, */ static noinline_for_stack unsigned long shrink_inactive_list(unsigned long nr_to_scan, struct mem_cgroup_zone *mz, - struct scan_control *sc, int priority, enum lru_list lru) + struct scan_control *sc, enum lru_list lru) { LIST_HEAD(page_list); unsigned long nr_scanned; @@ -1307,7 +1310,7 @@ shrink_inactive_list(unsigned long nr_to_scan, struct mem_cgroup_zone *mz, update_isolated_counts(mz, &page_list, &nr_anon, &nr_file); - nr_reclaimed = shrink_page_list(&page_list, mz, sc, priority, + nr_reclaimed = shrink_page_list(&page_list, mz, sc, &nr_dirty, &nr_writeback); spin_lock_irq(&zone->lru_lock); @@ -1356,13 +1359,14 @@ shrink_inactive_list(unsigned long nr_to_scan, struct mem_cgroup_zone *mz, * DEF_PRIORITY-6 For SWAP_CLUSTER_MAX isolated pages, throttle if any * isolated page is PageWriteback */ - if (nr_writeback && nr_writeback >= (nr_taken >> (DEF_PRIORITY-priority))) + if (nr_writeback && nr_writeback >= + (nr_taken >> (DEF_PRIORITY - sc->priority))) wait_iff_congested(zone, BLK_RW_ASYNC, HZ/10); trace_mm_vmscan_lru_shrink_inactive(zone->zone_pgdat->node_id, zone_idx(zone), nr_scanned, nr_reclaimed, - priority, + sc->priority, trace_shrink_flags(file)); return nr_reclaimed; } @@ -1426,7 +1430,7 @@ static void move_active_pages_to_lru(struct zone *zone, static void shrink_active_list(unsigned long nr_to_scan, struct mem_cgroup_zone *mz, struct scan_control *sc, - int priority, enum lru_list lru) + enum lru_list lru) { unsigned long nr_taken; unsigned long nr_scanned; @@ -1609,17 +1613,17 @@ static int inactive_list_is_low(struct mem_cgroup_zone *mz, int file) static unsigned long shrink_list(enum lru_list lru, unsigned long nr_to_scan, struct mem_cgroup_zone *mz, - struct scan_control *sc, int priority) + struct scan_control *sc) { int file = is_file_lru(lru); if (is_active_lru(lru)) { if (inactive_list_is_low(mz, file)) - shrink_active_list(nr_to_scan, mz, sc, priority, lru); + shrink_active_list(nr_to_scan, mz, sc, lru); return 0; } - return shrink_inactive_list(nr_to_scan, mz, sc, priority, lru); + return shrink_inactive_list(nr_to_scan, mz, sc, lru); } static int vmscan_swappiness(struct scan_control *sc) @@ -1638,7 +1642,7 @@ static int vmscan_swappiness(struct scan_control *sc) * nr[0] = anon pages to scan; nr[1] = file pages to scan */ static void get_scan_count(struct mem_cgroup_zone *mz, struct scan_control *sc, - unsigned long *nr, int priority) + unsigned long *nr) { unsigned long anon, file, free; unsigned long anon_prio, file_prio; @@ -1740,8 +1744,8 @@ out: unsigned long scan; scan = zone_nr_lru_pages(mz, lru); - if (priority || noswap || !vmscan_swappiness(sc)) { - scan >>= priority; + if (sc->priority || noswap || !vmscan_swappiness(sc)) { + scan >>= sc->priority; if (!scan && force_scan) scan = SWAP_CLUSTER_MAX; scan = div64_u64(scan * fraction[file], denominator); @@ -1751,11 +1755,11 @@ out: } /* Use reclaim/compaction for costly allocs or under memory pressure */ -static bool in_reclaim_compaction(int priority, struct scan_control *sc) +static bool in_reclaim_compaction(struct scan_control *sc) { if (COMPACTION_BUILD && sc->order && (sc->order > PAGE_ALLOC_COSTLY_ORDER || - priority < DEF_PRIORITY - 2)) + sc->priority < DEF_PRIORITY - 2)) return true; return false; @@ -1771,14 +1775,13 @@ static bool in_reclaim_compaction(int priority, struct scan_control *sc) static inline bool should_continue_reclaim(struct mem_cgroup_zone *mz, unsigned long nr_reclaimed, unsigned long nr_scanned, - int priority, struct scan_control *sc) { unsigned long pages_for_compaction; unsigned long inactive_lru_pages; /* If not in reclaim/compaction mode, stop */ - if (!in_reclaim_compaction(priority, sc)) + if (!in_reclaim_compaction(sc)) return false; /* Consider stopping depending on scan and reclaim activity */ @@ -1829,7 +1832,7 @@ static inline bool should_continue_reclaim(struct mem_cgroup_zone *mz, /* * This is a basic per-zone page freer. Used by both kswapd and direct reclaim. */ -static void shrink_mem_cgroup_zone(int priority, struct mem_cgroup_zone *mz, +static void shrink_mem_cgroup_zone(struct mem_cgroup_zone *mz, struct scan_control *sc) { unsigned long nr[NR_LRU_LISTS]; @@ -1842,7 +1845,7 @@ static void shrink_mem_cgroup_zone(int priority, struct mem_cgroup_zone *mz, restart: nr_reclaimed = 0; nr_scanned = sc->nr_scanned; - get_scan_count(mz, sc, nr, priority); + get_scan_count(mz, sc, nr); blk_start_plug(&plug); while (nr[LRU_INACTIVE_ANON] || nr[LRU_ACTIVE_FILE] || @@ -1854,7 +1857,7 @@ restart: nr[lru] -= nr_to_scan; nr_reclaimed += shrink_list(lru, nr_to_scan, - mz, sc, priority); + mz, sc); } } /* @@ -1865,7 +1868,8 @@ restart: * 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 && + sc->priority < DEF_PRIORITY) break; } blk_finish_plug(&plug); @@ -1877,24 +1881,22 @@ restart: */ if (inactive_anon_is_low(mz)) shrink_active_list(SWAP_CLUSTER_MAX, mz, - sc, priority, LRU_ACTIVE_ANON); + sc, LRU_ACTIVE_ANON); /* reclaim/compaction might need reclaim to continue */ if (should_continue_reclaim(mz, nr_reclaimed, - sc->nr_scanned - nr_scanned, - priority, sc)) + sc->nr_scanned - nr_scanned, sc)) goto restart; throttle_vm_writeout(sc->gfp_mask); } -static void shrink_zone(int priority, struct zone *zone, - struct scan_control *sc) +static void shrink_zone(struct zone *zone, struct scan_control *sc) { struct mem_cgroup *root = sc->target_mem_cgroup; struct mem_cgroup_reclaim_cookie reclaim = { .zone = zone, - .priority = priority, + .priority = sc->priority, }; struct mem_cgroup *memcg; @@ -1905,7 +1907,7 @@ static void shrink_zone(int priority, struct zone *zone, .zone = zone, }; - shrink_mem_cgroup_zone(priority, &mz, sc); + shrink_mem_cgroup_zone(&mz, sc); /* * Limit reclaim has historically picked one memcg and * scanned it with decreasing priority levels until @@ -1981,8 +1983,7 @@ static inline bool compaction_ready(struct zone *zone, struct scan_control *sc) * the caller that it should consider retrying the allocation instead of * further reclaim. */ -static bool shrink_zones(int priority, struct zonelist *zonelist, - struct scan_control *sc) +static bool shrink_zones(struct zonelist *zonelist, struct scan_control *sc) { struct zoneref *z; struct zone *zone; @@ -2009,7 +2010,8 @@ static bool shrink_zones(int priority, struct zonelist *zonelist, if (global_reclaim(sc)) { if (!cpuset_zone_allowed_hardwall(zone, GFP_KERNEL)) continue; - if (zone->all_unreclaimable && priority != DEF_PRIORITY) + if (zone->all_unreclaimable && + sc->priority != DEF_PRIORITY) continue; /* Let kswapd poll it */ if (COMPACTION_BUILD) { /* @@ -2041,7 +2043,7 @@ static bool shrink_zones(int priority, struct zonelist *zonelist, /* need some check for avoid more shrink_zone() */ } - shrink_zone(priority, zone, sc); + shrink_zone(zone, sc); } return aborted_reclaim; @@ -2092,7 +2094,6 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist, struct scan_control *sc, struct shrink_control *shrink) { - int priority; unsigned long total_scanned = 0; struct reclaim_state *reclaim_state = current->reclaim_state; struct zoneref *z; @@ -2105,9 +2106,9 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist, if (global_reclaim(sc)) count_vm_event(ALLOCSTALL); - for (priority = DEF_PRIORITY; priority >= 0; priority--) { + do { sc->nr_scanned = 0; - aborted_reclaim = shrink_zones(priority, zonelist, sc); + aborted_reclaim = shrink_zones(zonelist, sc); /* * Don't shrink slabs when reclaiming memory from @@ -2149,7 +2150,7 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist, /* Take a nap, wait for some writeback to complete */ if (!sc->hibernation_mode && sc->nr_scanned && - priority < DEF_PRIORITY - 2) { + sc->priority < DEF_PRIORITY - 2) { struct zone *preferred_zone; first_zones_zonelist(zonelist, gfp_zone(sc->gfp_mask), @@ -2157,7 +2158,7 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist, &preferred_zone); wait_iff_congested(preferred_zone, BLK_RW_ASYNC, HZ/10); } - } + } while (--sc->priority >= 0); out: delayacct_freepages_end(); @@ -2195,6 +2196,7 @@ unsigned long try_to_free_pages(struct zonelist *zonelist, int order, .may_unmap = 1, .may_swap = 1, .order = order, + .priority = DEF_PRIORITY, .target_mem_cgroup = NULL, .nodemask = nodemask, }; @@ -2227,6 +2229,7 @@ unsigned long mem_cgroup_shrink_node_zone(struct mem_cgroup *memcg, .may_unmap = 1, .may_swap = !noswap, .order = 0, + .priority = 0, .target_mem_cgroup = memcg, }; struct mem_cgroup_zone mz = { @@ -2237,7 +2240,7 @@ unsigned long mem_cgroup_shrink_node_zone(struct mem_cgroup *memcg, sc.gfp_mask = (gfp_mask & GFP_RECLAIM_MASK) | (GFP_HIGHUSER_MOVABLE & ~GFP_RECLAIM_MASK); - trace_mm_vmscan_memcg_softlimit_reclaim_begin(0, + trace_mm_vmscan_memcg_softlimit_reclaim_begin(sc.order, sc.may_writepage, sc.gfp_mask); @@ -2248,7 +2251,7 @@ unsigned long mem_cgroup_shrink_node_zone(struct mem_cgroup *memcg, * will pick up pages from other mem cgroup's as well. We hack * the priority and make it zero. */ - shrink_mem_cgroup_zone(0, &mz, &sc); + shrink_mem_cgroup_zone(&mz, &sc); trace_mm_vmscan_memcg_softlimit_reclaim_end(sc.nr_reclaimed); @@ -2269,6 +2272,7 @@ unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *memcg, .may_swap = !noswap, .nr_to_reclaim = SWAP_CLUSTER_MAX, .order = 0, + .priority = DEF_PRIORITY, .target_mem_cgroup = memcg, .nodemask = NULL, /* we don't care the placement */ .gfp_mask = (gfp_mask & GFP_RECLAIM_MASK) | @@ -2299,8 +2303,7 @@ unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *memcg, } #endif -static void age_active_anon(struct zone *zone, struct scan_control *sc, - int priority) +static void age_active_anon(struct zone *zone, struct scan_control *sc) { struct mem_cgroup *memcg; @@ -2316,7 +2319,7 @@ static void age_active_anon(struct zone *zone, struct scan_control *sc, if (inactive_anon_is_low(&mz)) shrink_active_list(SWAP_CLUSTER_MAX, &mz, - sc, priority, LRU_ACTIVE_ANON); + sc, LRU_ACTIVE_ANON); memcg = mem_cgroup_iter(NULL, memcg, NULL); } while (memcg); @@ -2425,7 +2428,6 @@ static unsigned long balance_pgdat(pg_data_t *pgdat, int order, { int all_zones_ok; unsigned long balanced; - int priority; int i; int end_zone = 0; /* Inclusive. 0 = ZONE_DMA */ unsigned long total_scanned; @@ -2449,11 +2451,12 @@ static unsigned long balance_pgdat(pg_data_t *pgdat, int order, }; loop_again: total_scanned = 0; + sc.priority = DEF_PRIORITY; sc.nr_reclaimed = 0; sc.may_writepage = !laptop_mode; count_vm_event(PAGEOUTRUN); - for (priority = DEF_PRIORITY; priority >= 0; priority--) { + do { unsigned long lru_pages = 0; int has_under_min_watermark_zone = 0; @@ -2470,14 +2473,15 @@ loop_again: if (!populated_zone(zone)) continue; - if (zone->all_unreclaimable && priority != DEF_PRIORITY) + if (zone->all_unreclaimable && + sc.priority != DEF_PRIORITY) continue; /* * Do some background aging of the anon list, to give * pages a chance to be referenced before reclaiming. */ - age_active_anon(zone, &sc, priority); + age_active_anon(zone, &sc); /* * If the number of buffer_heads in the machine @@ -2525,7 +2529,8 @@ loop_again: if (!populated_zone(zone)) continue; - if (zone->all_unreclaimable && priority != DEF_PRIORITY) + if (zone->all_unreclaimable && + sc.priority != DEF_PRIORITY) continue; sc.nr_scanned = 0; @@ -2569,7 +2574,7 @@ loop_again: !zone_watermark_ok_safe(zone, testorder, high_wmark_pages(zone) + balance_gap, end_zone, 0)) { - shrink_zone(priority, zone, &sc); + shrink_zone(zone, &sc); reclaim_state->reclaimed_slab = 0; nr_slab = shrink_slab(&shrink, sc.nr_scanned, lru_pages); @@ -2626,7 +2631,7 @@ loop_again: * OK, kswapd is getting into trouble. Take a nap, then take * another pass across the zones. */ - if (total_scanned && (priority < DEF_PRIORITY - 2)) { + if (total_scanned && (sc.priority < DEF_PRIORITY - 2)) { if (has_under_min_watermark_zone) count_vm_event(KSWAPD_SKIP_CONGESTION_WAIT); else @@ -2641,7 +2646,7 @@ loop_again: */ if (sc.nr_reclaimed >= SWAP_CLUSTER_MAX) break; - } + } while (--sc.priority >= 0); out: /* @@ -2691,7 +2696,8 @@ out: if (!populated_zone(zone)) continue; - if (zone->all_unreclaimable && priority != DEF_PRIORITY) + if (zone->all_unreclaimable && + sc.priority != DEF_PRIORITY) continue; /* Would compaction fail due to lack of free memory? */ @@ -2958,6 +2964,7 @@ unsigned long shrink_all_memory(unsigned long nr_to_reclaim) .nr_to_reclaim = nr_to_reclaim, .hibernation_mode = 1, .order = 0, + .priority = DEF_PRIORITY, }; struct shrink_control shrink = { .gfp_mask = sc.gfp_mask, @@ -3135,7 +3142,6 @@ static int __zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order) const unsigned long nr_pages = 1 << order; struct task_struct *p = current; struct reclaim_state reclaim_state; - int priority; struct scan_control sc = { .may_writepage = !!(zone_reclaim_mode & RECLAIM_WRITE), .may_unmap = !!(zone_reclaim_mode & RECLAIM_SWAP), @@ -3144,6 +3150,7 @@ static int __zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order) SWAP_CLUSTER_MAX), .gfp_mask = gfp_mask, .order = order, + .priority = ZONE_RECLAIM_PRIORITY, }; struct shrink_control shrink = { .gfp_mask = sc.gfp_mask, @@ -3166,11 +3173,9 @@ static int __zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order) * Free memory by calling shrink zone with increasing * priorities until we have enough memory freed. */ - priority = ZONE_RECLAIM_PRIORITY; do { - shrink_zone(priority, zone, &sc); - priority--; - } while (priority >= 0 && sc.nr_reclaimed < nr_pages); + shrink_zone(zone, &sc); + } while (sc.nr_reclaimed < nr_pages && --sc.priority >= 0); } nr_slab_pages0 = zone_page_state(zone, NR_SLAB_RECLAIMABLE); -- 2.7.4