On Fri 27-01-23 18:07:32, Ojaswin Mujoo wrote: > 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@xxxxxxxxxxxxx> > Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@xxxxxxxxx> Looks good to me. Feel free to add: Reviewed-by: Jan Kara <jack@xxxxxxx> Honza > --- > fs/ext4/ext4.h | 1 + > fs/ext4/mballoc.c | 12 ++++++++++++ > fs/ext4/mballoc.h | 1 + > 3 files changed, 14 insertions(+) > > diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h > index 6037b8e0af86..4ba2c95915eb 100644 > --- a/fs/ext4/ext4.h > +++ b/fs/ext4/ext4.h > @@ -1633,6 +1633,7 @@ 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 323604a2ff45..07a50a13751c 100644 > --- a/fs/ext4/mballoc.c > +++ b/fs/ext4/mballoc.c > @@ -2077,6 +2077,7 @@ 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 > @@ -2249,6 +2250,7 @@ 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; > @@ -2362,6 +2364,7 @@ void ext4_mb_scan_aligned(struct ext4_allocation_context *ac, > max = mb_find_extent(e4b, i, sbi->s_stripe, &ex); > if (max >= sbi->s_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); > @@ -2894,6 +2897,7 @@ 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", > @@ -2903,6 +2907,7 @@ 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", > @@ -2912,6 +2917,7 @@ 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])); > > @@ -2919,6 +2925,7 @@ 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)); > @@ -4216,7 +4223,12 @@ 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 f0087a85e366..004b8d163cc9 100644 > --- a/fs/ext4/mballoc.h > +++ b/fs/ext4/mballoc.h > @@ -193,6 +193,7 @@ 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; > -- > 2.31.1 > -- Jan Kara <jack@xxxxxxxx> SUSE Labs, CR