From d144427dbe3d024272c953870086308dffad25e5 Mon Sep 17 00:00:00 2001 From: Johannes Weiner Date: Sat, 30 Nov 2019 17:55:49 -0800 Subject: [PATCH 2316/2944] mm: vmscan: split shrink_node() into node part and memcgs part task #30476527 commit 0f6a5cff43d3bcd6aa54c9af267737249d02aa21 upstream This function is getting long and unwieldy, split out the memcg bits. The updated shrink_node() handles the generic (node) reclaim aspects: - global vmpressure notifications - writeback and congestion throttling - reclaim/compaction management - kswapd giving up on unreclaimable nodes It then calls a new shrink_node_memcgs() which handles cgroup specifics: - the cgroup tree traversal - memory.low considerations - per-cgroup slab shrinking callbacks - per-cgroup vmpressure notifications [hannes@cmpxchg.org: rename "root" to "target_memcg", per Roman] Link: http://lkml.kernel.org/r/20191025143640.GA386981@cmpxchg.org Link: http://lkml.kernel.org/r/20191022144803.302233-8-hannes@cmpxchg.org Signed-off-by: Johannes Weiner Reviewed-by: Roman Gushchin Reviewed-by: Shakeel Butt Acked-by: Michal Hocko Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: zhongjiang-ali Reviewed-by: Xunlei Pang --- mm/vmscan.c | 50 +++++++++++++++++++++++++++++--------------------- 1 file changed, 29 insertions(+), 21 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index fd0c4ce..b4622f7 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -2800,26 +2800,17 @@ static inline bool should_continue_reclaim(struct pglist_data *pgdat, return true; } -static bool shrink_node(pg_data_t *pgdat, struct scan_control *sc) +static void shrink_node_memcgs(pg_data_t *pgdat, struct scan_control *sc) { - struct reclaim_state *reclaim_state = current->reclaim_state; - struct mem_cgroup *root = sc->target_mem_cgroup; - unsigned long nr_reclaimed, nr_scanned; - bool reclaimable = false; + struct mem_cgroup *target_memcg = sc->target_mem_cgroup; struct mem_cgroup *memcg; -again: - memset(&sc->nr, 0, sizeof(sc->nr)); - - nr_reclaimed = sc->nr_reclaimed; - nr_scanned = sc->nr_scanned; - - memcg = mem_cgroup_iter(root, NULL, NULL); + memcg = mem_cgroup_iter(target_memcg, NULL, NULL); do { unsigned long reclaimed; unsigned long scanned; - switch (mem_cgroup_protected(root, memcg)) { + switch (mem_cgroup_protected(target_memcg, memcg)) { case MEMCG_PROT_MIN: /* * Hard protection. @@ -2860,11 +2851,27 @@ static bool shrink_node(pg_data_t *pgdat, struct scan_control *sc) * mark is satisfied. */ if (current_is_kswapd() && cgroup_reclaim(sc) && - is_wmark_ok(root, false)) { - mem_cgroup_iter_break(root, memcg); + is_wmark_ok(target_memcg, false)) { + mem_cgroup_iter_break(target_memcg, memcg); break; } - } while ((memcg = mem_cgroup_iter(root, memcg, NULL))); + } while ((memcg = mem_cgroup_iter(target_memcg, memcg, NULL))); +} + +static bool shrink_node(pg_data_t *pgdat, struct scan_control *sc) +{ + struct reclaim_state *reclaim_state = current->reclaim_state; + struct mem_cgroup *target_memcg = sc->target_mem_cgroup; + unsigned long nr_reclaimed, nr_scanned; + bool reclaimable = false; + +again: + memset(&sc->nr, 0, sizeof(sc->nr)); + + nr_reclaimed = sc->nr_reclaimed; + nr_scanned = sc->nr_scanned; + + shrink_node_memcgs(pgdat, sc); if (reclaim_state) { sc->nr_reclaimed += reclaim_state->reclaimed_slab; @@ -2872,7 +2879,7 @@ static bool shrink_node(pg_data_t *pgdat, struct scan_control *sc) } /* Record the subtree's reclaim efficiency */ - vmpressure(sc->gfp_mask, sc->target_mem_cgroup, true, + vmpressure(sc->gfp_mask, target_memcg, true, sc->nr_scanned - nr_scanned, sc->nr_reclaimed - nr_reclaimed); @@ -2901,7 +2908,7 @@ static bool shrink_node(pg_data_t *pgdat, struct scan_control *sc) if (!cgroup_reclaim(sc)) set_bit(PGDAT_WRITEBACK, &pgdat->flags); else - set_memcg_writeback(pgdat, root, true); + set_memcg_writeback(pgdat, target_memcg, true); } /* @@ -2918,7 +2925,7 @@ static bool shrink_node(pg_data_t *pgdat, struct scan_control *sc) if (!cgroup_reclaim(sc)) set_bit(PGDAT_DIRTY, &pgdat->flags); else - set_memcg_dirty(pgdat, root, true); + set_memcg_dirty(pgdat, target_memcg, true); } /* @@ -2937,7 +2944,7 @@ static bool shrink_node(pg_data_t *pgdat, struct scan_control *sc) */ if (cgroup_reclaim(sc) && writeback_throttling_sane(sc) && sc->nr.dirty && sc->nr.dirty == sc->nr.congested) - set_memcg_congestion(pgdat, root, true); + set_memcg_congestion(pgdat, target_memcg, true); /* * Stall direct reclaim for IO completions if underlying BDIs @@ -2946,7 +2953,8 @@ static bool shrink_node(pg_data_t *pgdat, struct scan_control *sc) * the LRU too quickly. */ if (!sc->hibernation_mode && !current_is_kswapd() && - current_may_throttle() && pgdat_memcg_congested(pgdat, root)) + current_may_throttle() && + pgdat_memcg_congested(pgdat, target_memcg)) wait_iff_congested(BLK_RW_ASYNC, HZ/10); if (should_continue_reclaim(pgdat, sc->nr_reclaimed - nr_reclaimed, -- 1.8.3.1