From: Harshad Shirwadkar harshadshirwadkar@gmail.com
[ Upstream commit a6c75eaf11032f4a3d2b3ce2265a194ac6e4a7f0 ]
Add new stats for measuring the performance of mballoc. This patch is forked from Artem Blagodarenko's work that can be found here:
https://github.com/lustre/lustre-release/blob/master/ldiskfs/kernel_patches/...
This patch reorganizes the stats by cr level. This is how the output looks like:
mballoc: reqs: 0 success: 0 groups_scanned: 0 cr0_stats: hits: 0 groups_considered: 0 useless_loops: 0 bad_suggestions: 0 cr1_stats: hits: 0 groups_considered: 0 useless_loops: 0 bad_suggestions: 0 cr2_stats: hits: 0 groups_considered: 0 useless_loops: 0 cr3_stats: hits: 0 groups_considered: 0 useless_loops: 0 extents_scanned: 0 goal_hits: 0 2^n_hits: 0 breaks: 0 lost: 0 buddies_generated: 0/40 buddies_time_used: 0 preallocated: 0 discarded: 0
Signed-off-by: Harshad Shirwadkar harshadshirwadkar@gmail.com Reviewed-by: Andreas Dilger adilger@dilger.ca Reviewed-by: Ritesh Harjani ritesh.list@gmail.com Link: https://lore.kernel.org/r/20210401172129.189766-4-harshadshirwadkar@gmail.co... Signed-off-by: Theodore Ts'o tytso@mit.edu Stable-dep-of: 5354b2af3406 ("ext4: allow ext4_get_group_info() to fail") Signed-off-by: Sasha Levin sashal@kernel.org --- fs/ext4/ext4.h | 5 ++++ fs/ext4/mballoc.c | 75 +++++++++++++++++++++++++++++++++++++++++++++-- fs/ext4/sysfs.c | 2 ++ 3 files changed, 80 insertions(+), 2 deletions(-)
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 5efd48d7c9a79..1de55d8e0d354 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -1535,9 +1535,13 @@ struct ext4_sb_info { atomic_t s_bal_success; /* we found long enough chunks */ atomic_t s_bal_allocated; /* in blocks */ atomic_t s_bal_ex_scanned; /* total extents scanned */ + atomic_t s_bal_groups_scanned; /* number of groups scanned */ atomic_t s_bal_goals; /* goal hits */ atomic_t s_bal_breaks; /* too long searches */ atomic_t s_bal_2orders; /* 2^order hits */ + atomic64_t s_bal_cX_groups_considered[4]; + atomic64_t s_bal_cX_hits[4]; + atomic64_t s_bal_cX_failed[4]; /* cX loop didn't find blocks */ atomic_t s_mb_buddies_generated; /* number of buddies generated */ atomic64_t s_mb_generation_time; atomic_t s_mb_lost_chunks; @@ -2784,6 +2788,7 @@ int ext4_fc_record_regions(struct super_block *sb, int ino, extern const struct seq_operations ext4_mb_seq_groups_ops; extern long ext4_mb_stats; extern long ext4_mb_max_to_scan; +extern int ext4_seq_mb_stats_show(struct seq_file *seq, void *offset); extern int ext4_mb_init(struct super_block *); extern int ext4_mb_release(struct super_block *); extern ext4_fsblk_t ext4_mb_new_blocks(handle_t *, diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index beee54480562a..aa51d1b837274 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -2151,6 +2151,8 @@ static int ext4_mb_good_group_nolock(struct ext4_allocation_context *ac, ext4_grpblk_t free; int ret = 0;
+ if (sbi->s_mb_stats) + atomic64_inc(&sbi->s_bal_cX_groups_considered[ac->ac_criteria]); if (should_lock) ext4_lock_group(sb, group); free = grp->bb_free; @@ -2425,6 +2427,9 @@ ext4_mb_regular_allocator(struct ext4_allocation_context *ac) if (ac->ac_status != AC_STATUS_CONTINUE) break; } + /* Processed all groups and haven't found blocks */ + if (sbi->s_mb_stats && i == ngroups) + atomic64_inc(&sbi->s_bal_cX_failed[cr]); }
if (ac->ac_b_ex.fe_len > 0 && ac->ac_status != AC_STATUS_FOUND && @@ -2454,6 +2459,9 @@ ext4_mb_regular_allocator(struct ext4_allocation_context *ac) goto repeat; } } + + if (sbi->s_mb_stats && ac->ac_status == AC_STATUS_FOUND) + atomic64_inc(&sbi->s_bal_cX_hits[ac->ac_criteria]); out: if (!err && ac->ac_status != AC_STATUS_FOUND && first_err) err = first_err; @@ -2553,6 +2561,67 @@ const struct seq_operations ext4_mb_seq_groups_ops = { .show = ext4_mb_seq_groups_show, };
+int ext4_seq_mb_stats_show(struct seq_file *seq, void *offset) +{ + struct super_block *sb = (struct super_block *)seq->private; + struct ext4_sb_info *sbi = EXT4_SB(sb); + + seq_puts(seq, "mballoc:\n"); + if (!sbi->s_mb_stats) { + seq_puts(seq, "\tmb stats collection turned off.\n"); + seq_puts(seq, "\tTo enable, please write "1" to sysfs file mb_stats.\n"); + return 0; + } + seq_printf(seq, "\treqs: %u\n", atomic_read(&sbi->s_bal_reqs)); + seq_printf(seq, "\tsuccess: %u\n", atomic_read(&sbi->s_bal_success)); + + seq_printf(seq, "\tgroups_scanned: %u\n", atomic_read(&sbi->s_bal_groups_scanned)); + + seq_puts(seq, "\tcr0_stats:\n"); + seq_printf(seq, "\t\thits: %llu\n", atomic64_read(&sbi->s_bal_cX_hits[0])); + seq_printf(seq, "\t\tgroups_considered: %llu\n", + atomic64_read(&sbi->s_bal_cX_groups_considered[0])); + seq_printf(seq, "\t\tuseless_loops: %llu\n", + atomic64_read(&sbi->s_bal_cX_failed[0])); + + seq_puts(seq, "\tcr1_stats:\n"); + seq_printf(seq, "\t\thits: %llu\n", atomic64_read(&sbi->s_bal_cX_hits[1])); + seq_printf(seq, "\t\tgroups_considered: %llu\n", + atomic64_read(&sbi->s_bal_cX_groups_considered[1])); + seq_printf(seq, "\t\tuseless_loops: %llu\n", + atomic64_read(&sbi->s_bal_cX_failed[1])); + + seq_puts(seq, "\tcr2_stats:\n"); + seq_printf(seq, "\t\thits: %llu\n", atomic64_read(&sbi->s_bal_cX_hits[2])); + seq_printf(seq, "\t\tgroups_considered: %llu\n", + atomic64_read(&sbi->s_bal_cX_groups_considered[2])); + seq_printf(seq, "\t\tuseless_loops: %llu\n", + atomic64_read(&sbi->s_bal_cX_failed[2])); + + seq_puts(seq, "\tcr3_stats:\n"); + seq_printf(seq, "\t\thits: %llu\n", atomic64_read(&sbi->s_bal_cX_hits[3])); + seq_printf(seq, "\t\tgroups_considered: %llu\n", + atomic64_read(&sbi->s_bal_cX_groups_considered[3])); + seq_printf(seq, "\t\tuseless_loops: %llu\n", + atomic64_read(&sbi->s_bal_cX_failed[3])); + seq_printf(seq, "\textents_scanned: %u\n", atomic_read(&sbi->s_bal_ex_scanned)); + seq_printf(seq, "\t\tgoal_hits: %u\n", atomic_read(&sbi->s_bal_goals)); + seq_printf(seq, "\t\t2^n_hits: %u\n", atomic_read(&sbi->s_bal_2orders)); + seq_printf(seq, "\t\tbreaks: %u\n", atomic_read(&sbi->s_bal_breaks)); + seq_printf(seq, "\t\tlost: %u\n", atomic_read(&sbi->s_mb_lost_chunks)); + + seq_printf(seq, "\tbuddies_generated: %u/%u\n", + atomic_read(&sbi->s_mb_buddies_generated), + ext4_get_groups_count(sb)); + seq_printf(seq, "\tbuddies_time_used: %llu\n", + atomic64_read(&sbi->s_mb_generation_time)); + seq_printf(seq, "\tpreallocated: %u\n", + atomic_read(&sbi->s_mb_preallocated)); + seq_printf(seq, "\tdiscarded: %u\n", + atomic_read(&sbi->s_mb_discarded)); + return 0; +} + static struct kmem_cache *get_groupinfo_cache(int blocksize_bits) { int cache_index = blocksize_bits - EXT4_MIN_BLOCK_LOG_SIZE; @@ -2980,9 +3049,10 @@ int ext4_mb_release(struct super_block *sb) atomic_read(&sbi->s_bal_reqs), atomic_read(&sbi->s_bal_success)); ext4_msg(sb, KERN_INFO, - "mballoc: %u extents scanned, %u goal hits, " + "mballoc: %u extents scanned, %u groups scanned, %u goal hits, " "%u 2^N hits, %u breaks, %u lost", atomic_read(&sbi->s_bal_ex_scanned), + atomic_read(&sbi->s_bal_groups_scanned), atomic_read(&sbi->s_bal_goals), atomic_read(&sbi->s_bal_2orders), atomic_read(&sbi->s_bal_breaks), @@ -3620,12 +3690,13 @@ static void ext4_mb_collect_stats(struct ext4_allocation_context *ac) { struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
- if (sbi->s_mb_stats && ac->ac_g_ex.fe_len > 1) { + if (sbi->s_mb_stats && ac->ac_g_ex.fe_len >= 1) { atomic_inc(&sbi->s_bal_reqs); atomic_add(ac->ac_b_ex.fe_len, &sbi->s_bal_allocated); if (ac->ac_b_ex.fe_len >= ac->ac_o_ex.fe_len) atomic_inc(&sbi->s_bal_success); atomic_add(ac->ac_found, &sbi->s_bal_ex_scanned); + atomic_add(ac->ac_groups_scanned, &sbi->s_bal_groups_scanned); if (ac->ac_g_ex.fe_start == ac->ac_b_ex.fe_start && ac->ac_g_ex.fe_group == ac->ac_b_ex.fe_group) atomic_inc(&sbi->s_bal_goals); diff --git a/fs/ext4/sysfs.c b/fs/ext4/sysfs.c index ce74cde6d8faa..b0bb4a92c9c94 100644 --- a/fs/ext4/sysfs.c +++ b/fs/ext4/sysfs.c @@ -539,6 +539,8 @@ int ext4_register_sysfs(struct super_block *sb) ext4_fc_info_show, sb); proc_create_seq_data("mb_groups", S_IRUGO, sbi->s_proc, &ext4_mb_seq_groups_ops, sb); + proc_create_single_data("mb_stats", 0444, sbi->s_proc, + ext4_seq_mb_stats_show, sb); } return 0; }