From 97a225e69a1f880886f33d2e65a7ace13f152caa Mon Sep 17 00:00:00 2001 From: Joonsoo Kim Date: Wed, 3 Jun 2020 15:59:01 -0700 Subject: mm/page_alloc: integrate classzone_idx and high_zoneidx classzone_idx is just different name for high_zoneidx now. So, integrate them and add some comment to struct alloc_context in order to reduce future confusion about the meaning of this variable. The accessor, ac_classzone_idx() is also removed since it isn't needed after integration. In addition to integration, this patch also renames high_zoneidx to highest_zoneidx since it represents more precise meaning. Signed-off-by: Joonsoo Kim Signed-off-by: Andrew Morton Reviewed-by: Baoquan He Acked-by: Vlastimil Babka Acked-by: David Rientjes Cc: Johannes Weiner Cc: Mel Gorman Cc: Michal Hocko Cc: Minchan Kim Cc: Ye Xiaolong Link: http://lkml.kernel.org/r/1587095923-7515-3-git-send-email-iamjoonsoo.kim@lge.com Signed-off-by: Linus Torvalds --- mm/vmscan.c | 105 +++++++++++++++++++++++++++++++----------------------------- 1 file changed, 55 insertions(+), 50 deletions(-) (limited to 'mm/vmscan.c') diff --git a/mm/vmscan.c b/mm/vmscan.c index b2f5deb3603c..18bfbee9a581 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -3131,8 +3131,8 @@ static bool allow_direct_reclaim(pg_data_t *pgdat) /* kswapd must be awake if processes are being throttled */ if (!wmark_ok && waitqueue_active(&pgdat->kswapd_wait)) { - if (READ_ONCE(pgdat->kswapd_classzone_idx) > ZONE_NORMAL) - WRITE_ONCE(pgdat->kswapd_classzone_idx, ZONE_NORMAL); + if (READ_ONCE(pgdat->kswapd_highest_zoneidx) > ZONE_NORMAL) + WRITE_ONCE(pgdat->kswapd_highest_zoneidx, ZONE_NORMAL); wake_up_interruptible(&pgdat->kswapd_wait); } @@ -3385,7 +3385,7 @@ static void age_active_anon(struct pglist_data *pgdat, } while (memcg); } -static bool pgdat_watermark_boosted(pg_data_t *pgdat, int classzone_idx) +static bool pgdat_watermark_boosted(pg_data_t *pgdat, int highest_zoneidx) { int i; struct zone *zone; @@ -3397,7 +3397,7 @@ static bool pgdat_watermark_boosted(pg_data_t *pgdat, int classzone_idx) * start prematurely when there is no boosting and a lower * zone is balanced. */ - for (i = classzone_idx; i >= 0; i--) { + for (i = highest_zoneidx; i >= 0; i--) { zone = pgdat->node_zones + i; if (!managed_zone(zone)) continue; @@ -3411,9 +3411,9 @@ static bool pgdat_watermark_boosted(pg_data_t *pgdat, int classzone_idx) /* * Returns true if there is an eligible zone balanced for the request order - * and classzone_idx + * and highest_zoneidx */ -static bool pgdat_balanced(pg_data_t *pgdat, int order, int classzone_idx) +static bool pgdat_balanced(pg_data_t *pgdat, int order, int highest_zoneidx) { int i; unsigned long mark = -1; @@ -3423,19 +3423,19 @@ static bool pgdat_balanced(pg_data_t *pgdat, int order, int classzone_idx) * Check watermarks bottom-up as lower zones are more likely to * meet watermarks. */ - for (i = 0; i <= classzone_idx; i++) { + for (i = 0; i <= highest_zoneidx; i++) { zone = pgdat->node_zones + i; if (!managed_zone(zone)) continue; mark = high_wmark_pages(zone); - if (zone_watermark_ok_safe(zone, order, mark, classzone_idx)) + if (zone_watermark_ok_safe(zone, order, mark, highest_zoneidx)) return true; } /* - * If a node has no populated zone within classzone_idx, it does not + * If a node has no populated zone within highest_zoneidx, it does not * need balancing by definition. This can happen if a zone-restricted * allocation tries to wake a remote kswapd. */ @@ -3461,7 +3461,8 @@ static void clear_pgdat_congested(pg_data_t *pgdat) * * Returns true if kswapd is ready to sleep */ -static bool prepare_kswapd_sleep(pg_data_t *pgdat, int order, int classzone_idx) +static bool prepare_kswapd_sleep(pg_data_t *pgdat, int order, + int highest_zoneidx) { /* * The throttled processes are normally woken up in balance_pgdat() as @@ -3483,7 +3484,7 @@ static bool prepare_kswapd_sleep(pg_data_t *pgdat, int order, int classzone_idx) if (pgdat->kswapd_failures >= MAX_RECLAIM_RETRIES) return true; - if (pgdat_balanced(pgdat, order, classzone_idx)) { + if (pgdat_balanced(pgdat, order, highest_zoneidx)) { clear_pgdat_congested(pgdat); return true; } @@ -3547,7 +3548,7 @@ static bool kswapd_shrink_node(pg_data_t *pgdat, * or lower is eligible for reclaim until at least one usable zone is * balanced. */ -static int balance_pgdat(pg_data_t *pgdat, int order, int classzone_idx) +static int balance_pgdat(pg_data_t *pgdat, int order, int highest_zoneidx) { int i; unsigned long nr_soft_reclaimed; @@ -3575,7 +3576,7 @@ static int balance_pgdat(pg_data_t *pgdat, int order, int classzone_idx) * stall or direct reclaim until kswapd is finished. */ nr_boost_reclaim = 0; - for (i = 0; i <= classzone_idx; i++) { + for (i = 0; i <= highest_zoneidx; i++) { zone = pgdat->node_zones + i; if (!managed_zone(zone)) continue; @@ -3593,7 +3594,7 @@ restart: bool balanced; bool ret; - sc.reclaim_idx = classzone_idx; + sc.reclaim_idx = highest_zoneidx; /* * If the number of buffer_heads exceeds the maximum allowed @@ -3623,7 +3624,7 @@ restart: * on the grounds that the normal reclaim should be enough to * re-evaluate if boosting is required when kswapd next wakes. */ - balanced = pgdat_balanced(pgdat, sc.order, classzone_idx); + balanced = pgdat_balanced(pgdat, sc.order, highest_zoneidx); if (!balanced && nr_boost_reclaim) { nr_boost_reclaim = 0; goto restart; @@ -3723,7 +3724,7 @@ out: if (boosted) { unsigned long flags; - for (i = 0; i <= classzone_idx; i++) { + for (i = 0; i <= highest_zoneidx; i++) { if (!zone_boosts[i]) continue; @@ -3738,7 +3739,7 @@ out: * As there is now likely space, wakeup kcompact to defragment * pageblocks. */ - wakeup_kcompactd(pgdat, pageblock_order, classzone_idx); + wakeup_kcompactd(pgdat, pageblock_order, highest_zoneidx); } snapshot_refaults(NULL, pgdat); @@ -3756,22 +3757,22 @@ out: } /* - * The pgdat->kswapd_classzone_idx is used to pass the highest zone index to be - * reclaimed by kswapd from the waker. If the value is MAX_NR_ZONES which is not - * a valid index then either kswapd runs for first time or kswapd couldn't sleep - * after previous reclaim attempt (node is still unbalanced). In that case - * return the zone index of the previous kswapd reclaim cycle. + * The pgdat->kswapd_highest_zoneidx is used to pass the highest zone index to + * be reclaimed by kswapd from the waker. If the value is MAX_NR_ZONES which is + * not a valid index then either kswapd runs for first time or kswapd couldn't + * sleep after previous reclaim attempt (node is still unbalanced). In that + * case return the zone index of the previous kswapd reclaim cycle. */ -static enum zone_type kswapd_classzone_idx(pg_data_t *pgdat, - enum zone_type prev_classzone_idx) +static enum zone_type kswapd_highest_zoneidx(pg_data_t *pgdat, + enum zone_type prev_highest_zoneidx) { - enum zone_type curr_idx = READ_ONCE(pgdat->kswapd_classzone_idx); + enum zone_type curr_idx = READ_ONCE(pgdat->kswapd_highest_zoneidx); - return curr_idx == MAX_NR_ZONES ? prev_classzone_idx : curr_idx; + return curr_idx == MAX_NR_ZONES ? prev_highest_zoneidx : curr_idx; } static void kswapd_try_to_sleep(pg_data_t *pgdat, int alloc_order, int reclaim_order, - unsigned int classzone_idx) + unsigned int highest_zoneidx) { long remaining = 0; DEFINE_WAIT(wait); @@ -3788,7 +3789,7 @@ static void kswapd_try_to_sleep(pg_data_t *pgdat, int alloc_order, int reclaim_o * eligible zone balanced that it's also unlikely that compaction will * succeed. */ - if (prepare_kswapd_sleep(pgdat, reclaim_order, classzone_idx)) { + if (prepare_kswapd_sleep(pgdat, reclaim_order, highest_zoneidx)) { /* * Compaction records what page blocks it recently failed to * isolate pages from and skips them in the future scanning. @@ -3801,18 +3802,19 @@ static void kswapd_try_to_sleep(pg_data_t *pgdat, int alloc_order, int reclaim_o * We have freed the memory, now we should compact it to make * allocation of the requested order possible. */ - wakeup_kcompactd(pgdat, alloc_order, classzone_idx); + wakeup_kcompactd(pgdat, alloc_order, highest_zoneidx); remaining = schedule_timeout(HZ/10); /* - * If woken prematurely then reset kswapd_classzone_idx and + * If woken prematurely then reset kswapd_highest_zoneidx and * order. The values will either be from a wakeup request or * the previous request that slept prematurely. */ if (remaining) { - WRITE_ONCE(pgdat->kswapd_classzone_idx, - kswapd_classzone_idx(pgdat, classzone_idx)); + WRITE_ONCE(pgdat->kswapd_highest_zoneidx, + kswapd_highest_zoneidx(pgdat, + highest_zoneidx)); if (READ_ONCE(pgdat->kswapd_order) < reclaim_order) WRITE_ONCE(pgdat->kswapd_order, reclaim_order); @@ -3827,7 +3829,7 @@ static void kswapd_try_to_sleep(pg_data_t *pgdat, int alloc_order, int reclaim_o * go fully to sleep until explicitly woken up. */ if (!remaining && - prepare_kswapd_sleep(pgdat, reclaim_order, classzone_idx)) { + prepare_kswapd_sleep(pgdat, reclaim_order, highest_zoneidx)) { trace_mm_vmscan_kswapd_sleep(pgdat->node_id); /* @@ -3869,7 +3871,7 @@ static void kswapd_try_to_sleep(pg_data_t *pgdat, int alloc_order, int reclaim_o static int kswapd(void *p) { unsigned int alloc_order, reclaim_order; - unsigned int classzone_idx = MAX_NR_ZONES - 1; + unsigned int highest_zoneidx = MAX_NR_ZONES - 1; pg_data_t *pgdat = (pg_data_t*)p; struct task_struct *tsk = current; const struct cpumask *cpumask = cpumask_of_node(pgdat->node_id); @@ -3893,22 +3895,24 @@ static int kswapd(void *p) set_freezable(); WRITE_ONCE(pgdat->kswapd_order, 0); - WRITE_ONCE(pgdat->kswapd_classzone_idx, MAX_NR_ZONES); + WRITE_ONCE(pgdat->kswapd_highest_zoneidx, MAX_NR_ZONES); for ( ; ; ) { bool ret; alloc_order = reclaim_order = READ_ONCE(pgdat->kswapd_order); - classzone_idx = kswapd_classzone_idx(pgdat, classzone_idx); + highest_zoneidx = kswapd_highest_zoneidx(pgdat, + highest_zoneidx); kswapd_try_sleep: kswapd_try_to_sleep(pgdat, alloc_order, reclaim_order, - classzone_idx); + highest_zoneidx); - /* Read the new order and classzone_idx */ + /* Read the new order and highest_zoneidx */ alloc_order = reclaim_order = READ_ONCE(pgdat->kswapd_order); - classzone_idx = kswapd_classzone_idx(pgdat, classzone_idx); + highest_zoneidx = kswapd_highest_zoneidx(pgdat, + highest_zoneidx); WRITE_ONCE(pgdat->kswapd_order, 0); - WRITE_ONCE(pgdat->kswapd_classzone_idx, MAX_NR_ZONES); + WRITE_ONCE(pgdat->kswapd_highest_zoneidx, MAX_NR_ZONES); ret = try_to_freeze(); if (kthread_should_stop()) @@ -3929,9 +3933,10 @@ kswapd_try_sleep: * but kcompactd is woken to compact for the original * request (alloc_order). */ - trace_mm_vmscan_kswapd_wake(pgdat->node_id, classzone_idx, + trace_mm_vmscan_kswapd_wake(pgdat->node_id, highest_zoneidx, alloc_order); - reclaim_order = balance_pgdat(pgdat, alloc_order, classzone_idx); + reclaim_order = balance_pgdat(pgdat, alloc_order, + highest_zoneidx); if (reclaim_order < alloc_order) goto kswapd_try_sleep; } @@ -3949,7 +3954,7 @@ kswapd_try_sleep: * needed. */ void wakeup_kswapd(struct zone *zone, gfp_t gfp_flags, int order, - enum zone_type classzone_idx) + enum zone_type highest_zoneidx) { pg_data_t *pgdat; enum zone_type curr_idx; @@ -3961,10 +3966,10 @@ void wakeup_kswapd(struct zone *zone, gfp_t gfp_flags, int order, return; pgdat = zone->zone_pgdat; - curr_idx = READ_ONCE(pgdat->kswapd_classzone_idx); + curr_idx = READ_ONCE(pgdat->kswapd_highest_zoneidx); - if (curr_idx == MAX_NR_ZONES || curr_idx < classzone_idx) - WRITE_ONCE(pgdat->kswapd_classzone_idx, classzone_idx); + if (curr_idx == MAX_NR_ZONES || curr_idx < highest_zoneidx) + WRITE_ONCE(pgdat->kswapd_highest_zoneidx, highest_zoneidx); if (READ_ONCE(pgdat->kswapd_order) < order) WRITE_ONCE(pgdat->kswapd_order, order); @@ -3974,8 +3979,8 @@ void wakeup_kswapd(struct zone *zone, gfp_t gfp_flags, int order, /* Hopeless node, leave it to direct reclaim if possible */ if (pgdat->kswapd_failures >= MAX_RECLAIM_RETRIES || - (pgdat_balanced(pgdat, order, classzone_idx) && - !pgdat_watermark_boosted(pgdat, classzone_idx))) { + (pgdat_balanced(pgdat, order, highest_zoneidx) && + !pgdat_watermark_boosted(pgdat, highest_zoneidx))) { /* * There may be plenty of free memory available, but it's too * fragmented for high-order allocations. Wake up kcompactd @@ -3984,11 +3989,11 @@ void wakeup_kswapd(struct zone *zone, gfp_t gfp_flags, int order, * ratelimit its work. */ if (!(gfp_flags & __GFP_DIRECT_RECLAIM)) - wakeup_kcompactd(pgdat, order, classzone_idx); + wakeup_kcompactd(pgdat, order, highest_zoneidx); return; } - trace_mm_vmscan_wakeup_kswapd(pgdat->node_id, classzone_idx, order, + trace_mm_vmscan_wakeup_kswapd(pgdat->node_id, highest_zoneidx, order, gfp_flags); wake_up_interruptible(&pgdat->kswapd_wait); } -- cgit v1.2.3