Viewing: ext4-add-mballoc-stats-proc-file.patch
commit a6c75eaf11032f4a3d2b3ce2265a194ac6e4a7f0
Author: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
AuthorDate: Thu Apr 1 10:21:25 2021 -0700
ext4: add mballoc stats proc file
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/patches/rhel8/ext4-simple-blockalloc.patch
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.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
---
Index: linux-stage/fs/ext4/ext4.h
===================================================================
--- linux-stage.orig/fs/ext4/ext4.h
+++ linux-stage/fs/ext4/ext4.h
@@ -1516,11 +1516,13 @@ 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 */
- /* cX loop didn't find blocks */
- atomic64_t s_bal_cX_failed[4];
+ 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 */
atomic64_t s_bal_cX_skipped[3];
atomic_t s_mb_buddies_generated; /* number of buddies generated */
atomic64_t s_mb_generation_time;
@@ -2702,6 +2704,7 @@ extern const struct file_operations ext4
extern int ext4_mb_seq_last_start_seq_show(struct seq_file *m, void *v);
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 *,
Index: linux-stage/fs/ext4/mballoc.c
===================================================================
--- linux-stage.orig/fs/ext4/mballoc.c
+++ linux-stage/fs/ext4/mballoc.c
@@ -2191,10 +2191,13 @@ static int ext4_mb_good_group_nolock(str
{
struct ext4_group_info *grp = ext4_get_group_info(ac->ac_sb, group);
struct super_block *sb = ac->ac_sb;
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
bool should_lock = ac->ac_flags & EXT4_MB_STRICT_CHECK;
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;
@@ -2488,7 +2491,7 @@ repeat:
break;
}
/* Processed all groups and haven't found blocks */
- if (i == ngroups)
+ if (sbi->s_mb_stats && i == ngroups)
atomic64_inc(&sbi->s_bal_cX_failed[cr]);
}
@@ -2517,6 +2520,9 @@ repeat:
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;
@@ -2623,6 +2629,67 @@ const struct seq_operations ext4_mb_seq_
.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", (unsigned long long)atomic64_read(&sbi->s_bal_cX_hits[0]));
+ seq_printf(seq, "\t\tgroups_considered: %llu\n",
+ (unsigned long long)atomic64_read(&sbi->s_bal_cX_groups_considered[0]));
+ seq_printf(seq, "\t\tuseless_loops: %llu\n",
+ (unsigned long long)atomic64_read(&sbi->s_bal_cX_failed[0]));
+
+ seq_puts(seq, "\tcr1_stats:\n");
+ seq_printf(seq, "\t\thits: %llu\n", (unsigned long long)atomic64_read(&sbi->s_bal_cX_hits[1]));
+ seq_printf(seq, "\t\tgroups_considered: %llu\n",
+ (unsigned long long)atomic64_read(&sbi->s_bal_cX_groups_considered[1]));
+ seq_printf(seq, "\t\tuseless_loops: %llu\n",
+ (unsigned long long)atomic64_read(&sbi->s_bal_cX_failed[1]));
+
+ seq_puts(seq, "\tcr2_stats:\n");
+ seq_printf(seq, "\t\thits: %llu\n", (unsigned long long)atomic64_read(&sbi->s_bal_cX_hits[2]));
+ seq_printf(seq, "\t\tgroups_considered: %llu\n",
+ (unsigned long long)atomic64_read(&sbi->s_bal_cX_groups_considered[2]));
+ seq_printf(seq, "\t\tuseless_loops: %llu\n",
+ (unsigned long long)atomic64_read(&sbi->s_bal_cX_failed[2]));
+
+ seq_puts(seq, "\tcr3_stats:\n");
+ seq_printf(seq, "\t\thits: %llu\n", (unsigned long long)atomic64_read(&sbi->s_bal_cX_hits[3]));
+ seq_printf(seq, "\t\tgroups_considered: %llu\n",
+ (unsigned long long)atomic64_read(&sbi->s_bal_cX_groups_considered[3]));
+ seq_printf(seq, "\t\tuseless_loops: %llu\n",
+ (unsigned long long)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",
+ (unsigned long long)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 int ext4_mb_check_and_update_prealloc(struct ext4_sb_info *sbi,
char *str, size_t cnt,
int update)
@@ -2777,97 +2844,6 @@ const struct file_operations ext4_seq_mb
.write = ext4_mb_last_group_write,
};
-static int mb_seq_alloc_show(struct seq_file *seq, void *v)
-{
- struct super_block *sb = seq->private;
- struct ext4_sb_info *sbi = EXT4_SB(sb);
-
- seq_printf(seq, "mballoc:\n");
- seq_printf(seq, "\tblocks: %u\n", atomic_read(&sbi->s_bal_allocated));
- 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, "\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, "\tuseless_c0_loops: %llu\n",
- (unsigned long long)atomic64_read(&sbi->s_bal_cX_failed[0]));
- seq_printf(seq, "\tuseless_c1_loops: %llu\n",
- (unsigned long long)atomic64_read(&sbi->s_bal_cX_failed[1]));
- seq_printf(seq, "\tuseless_c2_loops: %llu\n",
- (unsigned long long)atomic64_read(&sbi->s_bal_cX_failed[2]));
- seq_printf(seq, "\tuseless_c3_loops: %llu\n",
- (unsigned long long)atomic64_read(&sbi->s_bal_cX_failed[3]));
- seq_printf(seq, "\tskipped_c0_loops: %llu\n",
- (unsigned long long)atomic64_read(&sbi->s_bal_cX_skipped[0]));
- seq_printf(seq, "\tskipped_c1_loops: %llu\n",
- (unsigned long long)atomic64_read(&sbi->s_bal_cX_skipped[1]));
- seq_printf(seq, "\tskipped_c2_loops: %llu\n",
- (unsigned long long)atomic64_read(&sbi->s_bal_cX_skipped[2]));
- seq_printf(seq, "\tbuddies_generated: %u\n",
- atomic_read(&sbi->s_mb_buddies_generated));
- seq_printf(seq, "\tbuddies_time_used: %llu\n",
- (unsigned long long)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 ssize_t mb_seq_alloc_write(struct file *file,
- const char __user *buf,
- size_t cnt, loff_t *pos)
-{
- struct ext4_sb_info *sbi = EXT4_SB(PDE_DATA(file_inode(file)));
-
- atomic_set(&sbi->s_bal_allocated, 0),
- atomic_set(&sbi->s_bal_reqs, 0),
- atomic_set(&sbi->s_bal_success, 0);
-
- atomic_set(&sbi->s_bal_ex_scanned, 0),
- atomic_set(&sbi->s_bal_goals, 0),
- atomic_set(&sbi->s_bal_2orders, 0),
- atomic_set(&sbi->s_bal_breaks, 0),
- atomic_set(&sbi->s_mb_lost_chunks, 0);
-
- atomic64_set(&sbi->s_bal_cX_failed[0], 0),
- atomic64_set(&sbi->s_bal_cX_failed[1], 0),
- atomic64_set(&sbi->s_bal_cX_failed[2], 0);
- atomic64_set(&sbi->s_bal_cX_failed[3], 0);
-
- atomic64_set(&sbi->s_bal_cX_skipped[0], 0),
- atomic64_set(&sbi->s_bal_cX_skipped[1], 0),
- atomic64_set(&sbi->s_bal_cX_skipped[2], 0);
-
-
- atomic_set(&sbi->s_mb_buddies_generated, 0);
- atomic64_set(&sbi->s_mb_generation_time, 0);
-
- atomic_set(&sbi->s_mb_preallocated, 0),
- atomic_set(&sbi->s_mb_discarded, 0);
-
- return cnt;
-}
-
-static int mb_seq_alloc_open(struct inode *inode, struct file *file)
-{
- return single_open(file, mb_seq_alloc_show, PDE_DATA(inode));
-}
-
-const struct file_operations ext4_mb_seq_alloc_fops = {
- .owner = THIS_MODULE,
- .open = mb_seq_alloc_open,
- .read = seq_read,
- .llseek = seq_lseek,
- .release = single_release,
- .write = mb_seq_alloc_write,
-};
-
int ext4_mb_seq_last_start_seq_show(struct seq_file *m, void *v)
{
struct ext4_sb_info *sbi = EXT4_SB(m->private);
@@ -3350,9 +3326,10 @@ int ext4_mb_release(struct super_block *
(unsigned long long)atomic64_read(&sbi->s_bal_cX_skipped[1]),
(unsigned long long)atomic64_read(&sbi->s_bal_cX_skipped[2]));
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),
@@ -3871,12 +3848,13 @@ static void ext4_mb_collect_stats(struct
{
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);
Index: linux-stage/fs/ext4/sysfs.c
===================================================================
--- linux-stage.orig/fs/ext4/sysfs.c
+++ linux-stage/fs/ext4/sysfs.c
@@ -477,14 +477,14 @@ int ext4_register_sysfs(struct super_blo
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);
proc_create_data("prealloc_table", S_IRUGO, sbi->s_proc,
&ext4_seq_prealloc_table_fops, sb);
proc_create_data("mb_last_group", S_IRUGO, sbi->s_proc,
&ext4_seq_mb_last_group_fops, sb);
proc_create_single_data("mb_last_start", S_IRUGO, sbi->s_proc,
ext4_mb_seq_last_start_seq_show, sb);
- proc_create_data("mb_alloc_stats", S_IFREG | S_IRUGO | S_IWUSR,
- sbi->s_proc, &ext4_mb_seq_alloc_fops, sb);
}
return 0;
}
