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authorOjaswin Mujoo <ojaswin@linux.ibm.com>2023-05-30 15:33:43 +0300
committerTheodore Ts'o <tytso@mit.edu>2023-06-27 02:34:56 +0300
commitfdd9a00943a5f6687937628e01506dad697c9140 (patch)
tree2e59e98f58f67ccbc97c660477f35d12f1e0aa57
parent4eb7a4a1a33bdaf259fca8528f2546c90ad18f0d (diff)
downloadlinux-fdd9a00943a5f6687937628e01506dad697c9140.tar.xz
ext4: Add per CR extent scanned counter
This gives better visibility into the number of extents scanned in each particular CR. For example, this information can be used to see how out block group scanning logic is performing when the BG is fragmented. Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com> Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/55bb6d80f6e22ed2a5a830aa045572bdffc8b1b9.1685449706.git.ojaswin@linux.ibm.com Signed-off-by: Theodore Ts'o <tytso@mit.edu>
-rw-r--r--fs/ext4/ext4.h1
-rw-r--r--fs/ext4/mballoc.c12
-rw-r--r--fs/ext4/mballoc.h1
3 files changed, 14 insertions, 0 deletions
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 914475cbb060..34ec65126ea7 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1555,6 +1555,7 @@ 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_cX_ex_scanned[EXT4_MB_NUM_CRS]; /* 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 */
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 4359280d2fa7..e28731426ee5 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -2103,6 +2103,7 @@ static void ext4_mb_measure_extent(struct ext4_allocation_context *ac,
BUG_ON(ac->ac_status != AC_STATUS_CONTINUE);
ac->ac_found++;
+ ac->ac_cX_found[ac->ac_criteria]++;
/*
* The special case - take what you catch first
@@ -2277,6 +2278,7 @@ void ext4_mb_simple_scan_group(struct ext4_allocation_context *ac,
break;
}
ac->ac_found++;
+ ac->ac_cX_found[ac->ac_criteria]++;
ac->ac_b_ex.fe_len = 1 << i;
ac->ac_b_ex.fe_start = k << i;
@@ -2392,6 +2394,7 @@ void ext4_mb_scan_aligned(struct ext4_allocation_context *ac,
max = mb_find_extent(e4b, i, stripe, &ex);
if (max >= stripe) {
ac->ac_found++;
+ ac->ac_cX_found[ac->ac_criteria]++;
ex.fe_logical = 0xDEADF00D; /* debug value */
ac->ac_b_ex = ex;
ext4_mb_use_best_found(ac, e4b);
@@ -2929,6 +2932,7 @@ int ext4_seq_mb_stats_show(struct seq_file *seq, void *offset)
seq_printf(seq, "\t\thits: %llu\n", atomic64_read(&sbi->s_bal_cX_hits[CR0]));
seq_printf(seq, "\t\tgroups_considered: %llu\n",
atomic64_read(&sbi->s_bal_cX_groups_considered[CR0]));
+ seq_printf(seq, "\t\textents_scanned: %u\n", atomic_read(&sbi->s_bal_cX_ex_scanned[CR0]));
seq_printf(seq, "\t\tuseless_loops: %llu\n",
atomic64_read(&sbi->s_bal_cX_failed[CR0]));
seq_printf(seq, "\t\tbad_suggestions: %u\n",
@@ -2938,6 +2942,7 @@ int ext4_seq_mb_stats_show(struct seq_file *seq, void *offset)
seq_printf(seq, "\t\thits: %llu\n", atomic64_read(&sbi->s_bal_cX_hits[CR1]));
seq_printf(seq, "\t\tgroups_considered: %llu\n",
atomic64_read(&sbi->s_bal_cX_groups_considered[CR1]));
+ seq_printf(seq, "\t\textents_scanned: %u\n", atomic_read(&sbi->s_bal_cX_ex_scanned[CR1]));
seq_printf(seq, "\t\tuseless_loops: %llu\n",
atomic64_read(&sbi->s_bal_cX_failed[CR1]));
seq_printf(seq, "\t\tbad_suggestions: %u\n",
@@ -2947,6 +2952,7 @@ int ext4_seq_mb_stats_show(struct seq_file *seq, void *offset)
seq_printf(seq, "\t\thits: %llu\n", atomic64_read(&sbi->s_bal_cX_hits[CR2]));
seq_printf(seq, "\t\tgroups_considered: %llu\n",
atomic64_read(&sbi->s_bal_cX_groups_considered[CR2]));
+ seq_printf(seq, "\t\textents_scanned: %u\n", atomic_read(&sbi->s_bal_cX_ex_scanned[CR2]));
seq_printf(seq, "\t\tuseless_loops: %llu\n",
atomic64_read(&sbi->s_bal_cX_failed[CR2]));
@@ -2954,6 +2960,7 @@ int ext4_seq_mb_stats_show(struct seq_file *seq, void *offset)
seq_printf(seq, "\t\thits: %llu\n", atomic64_read(&sbi->s_bal_cX_hits[CR3]));
seq_printf(seq, "\t\tgroups_considered: %llu\n",
atomic64_read(&sbi->s_bal_cX_groups_considered[CR3]));
+ seq_printf(seq, "\t\textents_scanned: %u\n", atomic_read(&sbi->s_bal_cX_ex_scanned[CR3]));
seq_printf(seq, "\t\tuseless_loops: %llu\n",
atomic64_read(&sbi->s_bal_cX_failed[CR3]));
seq_printf(seq, "\textents_scanned: %u\n", atomic_read(&sbi->s_bal_ex_scanned));
@@ -4393,7 +4400,12 @@ static void ext4_mb_collect_stats(struct ext4_allocation_context *ac)
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);
+ for (int i=0; i<EXT4_MB_NUM_CRS; i++) {
+ atomic_add(ac->ac_cX_found[i], &sbi->s_bal_cX_ex_scanned[i]);
+ }
+
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)
diff --git a/fs/ext4/mballoc.h b/fs/ext4/mballoc.h
index 24b666e558f1..acfdc204e15d 100644
--- a/fs/ext4/mballoc.h
+++ b/fs/ext4/mballoc.h
@@ -184,6 +184,7 @@ struct ext4_allocation_context {
__u16 ac_groups_scanned;
__u16 ac_groups_linear_remaining;
__u16 ac_found;
+ __u16 ac_cX_found[EXT4_MB_NUM_CRS];
__u16 ac_tail;
__u16 ac_buddy;
__u8 ac_status;