From 520f897a3554b0665af1ae5d5ba286f290cecf5c Mon Sep 17 00:00:00 2001 From: Yang Guo Date: Wed, 28 Aug 2019 11:19:23 -0400 Subject: [PATCH] ext4: use percpu_counters for extent_status cache hits/misses MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit @es_stats_cache_hits and @es_stats_cache_misses are accessed frequently in ext4_es_lookup_extent function, it would influence the ext4 read/write performance in NUMA system. Let's optimize it using percpu_counter, it is profitable for the performance. The test command is as below: fio -name=randwrite -numjobs=8 -filename=/mnt/test1 -rw=randwrite -ioengine=libaio -direct=1 -iodepth=64 -sync=0 -norandommap -group_reporting -runtime=120 -time_based -bs=4k -size=5G And the result is better 10% than the initial implement: without the patch，IOPS=197k, BW=770MiB/s (808MB/s)(90.3GiB/120002msec) with the patch, IOPS=218k, BW=852MiB/s (894MB/s)(99.9GiB/120002msec) Cc: "Theodore Ts'o" Cc: Andreas Dilger Cc: Eric Biggers Signed-off-by: Yang Guo Signed-off-by: Shaokun Zhang --- fs/ext4/extents_status.c | 37 ++++++++++++++++++++++++------------- fs/ext4/extents_status.h | 4 ++-- 2 files changed, 26 insertions(+), 15 deletions(-) diff --git a/fs/ext4/extents_status.c b/fs/ext4/extents_status.c index 5efbb116fba0..d996b44d2265 100644 --- a/fs/ext4/extents_status.c +++ b/fs/ext4/extents_status.c @@ -948,7 +948,7 @@ out: es->es_pblk = es1->es_pblk; if (!ext4_es_is_referenced(es1)) ext4_es_set_referenced(es1); - stats->es_stats_cache_hits++; + percpu_counter_inc(&stats->es_stats_cache_hits); if (next_lblk) { node = rb_next(&es1->rb_node); if (node) { @@ -959,7 +959,7 @@ out: *next_lblk = 0; } } else { - stats->es_stats_cache_misses++; + percpu_counter_inc(&stats->es_stats_cache_misses); } read_unlock(&EXT4_I(inode)->i_es_lock); @@ -1586,9 +1586,9 @@ int ext4_seq_es_shrinker_info_show(struct seq_file *seq, void *v) seq_printf(seq, "stats:\n %lld objects\n %lld reclaimable objects\n", percpu_counter_sum_positive(&es_stats->es_stats_all_cnt), percpu_counter_sum_positive(&es_stats->es_stats_shk_cnt)); - seq_printf(seq, " %lu/%lu cache hits/misses\n", - es_stats->es_stats_cache_hits, - es_stats->es_stats_cache_misses); + seq_printf(seq, " %lld/%lld cache hits/misses\n", + percpu_counter_sum_positive(&es_stats->es_stats_cache_hits), + percpu_counter_sum_positive(&es_stats->es_stats_cache_misses)); if (inode_cnt) seq_printf(seq, " %d inodes on list\n", inode_cnt); @@ -1615,35 +1615,46 @@ int ext4_es_register_shrinker(struct ext4_sb_info *sbi) sbi->s_es_nr_inode = 0; spin_lock_init(&sbi->s_es_lock); sbi->s_es_stats.es_stats_shrunk = 0; - sbi->s_es_stats.es_stats_cache_hits = 0; - sbi->s_es_stats.es_stats_cache_misses = 0; + err = percpu_counter_init(&sbi->s_es_stats.es_stats_cache_hits, 0, + GFP_KERNEL); + if (err) + return err; + err = percpu_counter_init(&sbi->s_es_stats.es_stats_cache_misses, 0, + GFP_KERNEL); + if (err) + goto err1; sbi->s_es_stats.es_stats_scan_time = 0; sbi->s_es_stats.es_stats_max_scan_time = 0; err = percpu_counter_init(&sbi->s_es_stats.es_stats_all_cnt, 0, GFP_KERNEL); if (err) - return err; + goto err2; err = percpu_counter_init(&sbi->s_es_stats.es_stats_shk_cnt, 0, GFP_KERNEL); if (err) - goto err1; + goto err3; sbi->s_es_shrinker.scan_objects = ext4_es_scan; sbi->s_es_shrinker.count_objects = ext4_es_count; sbi->s_es_shrinker.seeks = DEFAULT_SEEKS; err = register_shrinker(&sbi->s_es_shrinker); if (err) - goto err2; + goto err4; return 0; - -err2: +err4: percpu_counter_destroy(&sbi->s_es_stats.es_stats_shk_cnt); -err1: +err3: percpu_counter_destroy(&sbi->s_es_stats.es_stats_all_cnt); +err2: + percpu_counter_destroy(&sbi->s_es_stats.es_stats_cache_misses); +err1: + percpu_counter_destroy(&sbi->s_es_stats.es_stats_cache_hits); return err; } void ext4_es_unregister_shrinker(struct ext4_sb_info *sbi) { + percpu_counter_destroy(&sbi->s_es_stats.es_stats_cache_hits); + percpu_counter_destroy(&sbi->s_es_stats.es_stats_cache_misses); percpu_counter_destroy(&sbi->s_es_stats.es_stats_all_cnt); percpu_counter_destroy(&sbi->s_es_stats.es_stats_shk_cnt); unregister_shrinker(&sbi->s_es_shrinker); diff --git a/fs/ext4/extents_status.h b/fs/ext4/extents_status.h index 5e5c4a40d863..825313c59752 100644 --- a/fs/ext4/extents_status.h +++ b/fs/ext4/extents_status.h @@ -70,8 +70,8 @@ struct ext4_es_tree { struct ext4_es_stats { unsigned long es_stats_shrunk; - unsigned long es_stats_cache_hits; - unsigned long es_stats_cache_misses; + struct percpu_counter es_stats_cache_hits; + struct percpu_counter es_stats_cache_misses; u64 es_stats_scan_time; u64 es_stats_max_scan_time; struct percpu_counter es_stats_all_cnt;