2021-03-15 17:40:14

by Harshad Shirwadkar

[permalink] [raw]
Subject: [PATCH v4 6/6] ext4: add proc files to monitor new structures

This patch adds a new file "mb_structs_summary" which allows us to see
the summary of the new allocator structures added in this
series. Here's the sample output of file:

optimize_scan: 1
max_free_order_lists:
list_order_0_groups: 0
list_order_1_groups: 0
list_order_2_groups: 0
list_order_3_groups: 0
list_order_4_groups: 0
list_order_5_groups: 0
list_order_6_groups: 0
list_order_7_groups: 0
list_order_8_groups: 0
list_order_9_groups: 0
list_order_10_groups: 0
list_order_11_groups: 0
list_order_12_groups: 0
list_order_13_groups: 40
fragment_size_tree:
tree_min: 16384
tree_max: 32768
tree_nodes: 40

Signed-off-by: Harshad Shirwadkar <[email protected]>
---
fs/ext4/ext4.h | 1 +
fs/ext4/mballoc.c | 86 +++++++++++++++++++++++++++++++++++++++++++++++
fs/ext4/sysfs.c | 2 ++
3 files changed, 89 insertions(+)

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 5930c8cb5159..f6a36a0e07c1 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -2822,6 +2822,7 @@ int __init ext4_fc_init_dentry_cache(void);

/* mballoc.c */
extern const struct seq_operations ext4_mb_seq_groups_ops;
+extern const struct seq_operations ext4_mb_seq_structs_summary_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);
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index fb53ec1e1d37..7ce1d1283fd9 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -2945,6 +2945,92 @@ int ext4_seq_mb_stats_show(struct seq_file *seq, void *offset)
return 0;
}

+static void *ext4_mb_seq_structs_summary_start(struct seq_file *seq, loff_t *pos)
+{
+ struct super_block *sb = PDE_DATA(file_inode(seq->file));
+ unsigned long position;
+
+ read_lock(&EXT4_SB(sb)->s_mb_rb_lock);
+
+ if (*pos < 0 || *pos >= MB_NUM_ORDERS(sb) + 1)
+ return NULL;
+ position = *pos + 1;
+ return (void *) ((unsigned long) position);
+}
+
+static void *ext4_mb_seq_structs_summary_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+ struct super_block *sb = PDE_DATA(file_inode(seq->file));
+ unsigned long position;
+
+ ++*pos;
+ if (*pos < 0 || *pos >= MB_NUM_ORDERS(sb) + 1)
+ return NULL;
+ position = *pos + 1;
+ return (void *) ((unsigned long) position);
+}
+
+static int ext4_mb_seq_structs_summary_show(struct seq_file *seq, void *v)
+{
+ struct super_block *sb = PDE_DATA(file_inode(seq->file));
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+ unsigned long position = ((unsigned long) v);
+ struct ext4_group_info *grp;
+ struct rb_node *n;
+ unsigned int count, min, max;
+
+ position--;
+ if (position >= MB_NUM_ORDERS(sb)) {
+ seq_puts(seq, "fragment_size_tree:\n");
+ n = rb_first(&sbi->s_mb_avg_fragment_size_root);
+ if (!n) {
+ seq_puts(seq, "\ttree_min: 0\n\ttree_max: 0\n\ttree_nodes: 0\n");
+ return 0;
+ }
+ grp = rb_entry(n, struct ext4_group_info, bb_avg_fragment_size_rb);
+ min = grp->bb_fragments ? grp->bb_free / grp->bb_fragments : 0;
+ count = 1;
+ while (rb_next(n)) {
+ count++;
+ n = rb_next(n);
+ }
+ grp = rb_entry(n, struct ext4_group_info, bb_avg_fragment_size_rb);
+ max = grp->bb_fragments ? grp->bb_free / grp->bb_fragments : 0;
+
+ seq_printf(seq, "\ttree_min: %u\n\ttree_max: %u\n\ttree_nodes: %u\n",
+ min, max, count);
+ return 0;
+ }
+
+ if (position == 0) {
+ seq_printf(seq, "optimize_scan: %d\n",
+ test_opt2(sb, MB_OPTIMIZE_SCAN) ? 1 : 0);
+ seq_puts(seq, "max_free_order_lists:\n");
+ }
+ count = 0;
+ list_for_each_entry(grp, &sbi->s_mb_largest_free_orders[position],
+ bb_largest_free_order_node)
+ count++;
+ seq_printf(seq, "\tlist_order_%u_groups: %u\n",
+ (unsigned int)position, count);
+
+ return 0;
+}
+
+static void ext4_mb_seq_structs_summary_stop(struct seq_file *seq, void *v)
+{
+ struct super_block *sb = PDE_DATA(file_inode(seq->file));
+
+ read_unlock(&EXT4_SB(sb)->s_mb_rb_lock);
+}
+
+const struct seq_operations ext4_mb_seq_structs_summary_ops = {
+ .start = ext4_mb_seq_structs_summary_start,
+ .next = ext4_mb_seq_structs_summary_next,
+ .stop = ext4_mb_seq_structs_summary_stop,
+ .show = ext4_mb_seq_structs_summary_show,
+};
+
static struct kmem_cache *get_groupinfo_cache(int blocksize_bits)
{
int cache_index = blocksize_bits - EXT4_MIN_BLOCK_LOG_SIZE;
diff --git a/fs/ext4/sysfs.c b/fs/ext4/sysfs.c
index 16b8a838f631..4a3b78684f83 100644
--- a/fs/ext4/sysfs.c
+++ b/fs/ext4/sysfs.c
@@ -525,6 +525,8 @@ int ext4_register_sysfs(struct super_block *sb)
&ext4_mb_seq_groups_ops, sb);
proc_create_single_data("mb_stats", 0444, sbi->s_proc,
ext4_seq_mb_stats_show, sb);
+ proc_create_seq_data("mb_structs_summary", 0444, sbi->s_proc,
+ &ext4_mb_seq_structs_summary_ops, sb);
}
return 0;
}
--
2.31.0.rc2.261.g7f71774620-goog


2021-03-15 21:36:30

by Andreas Dilger

[permalink] [raw]
Subject: Re: [PATCH v4 6/6] ext4: add proc files to monitor new structures

On Mar 15, 2021, at 11:37 AM, Harshad Shirwadkar <[email protected]> wrote:
>
> This patch adds a new file "mb_structs_summary" which allows us to see
> the summary of the new allocator structures added in this
> series. Here's the sample output of file:
>
> optimize_scan: 1
> max_free_order_lists:
> list_order_0_groups: 0
> list_order_1_groups: 0
> list_order_2_groups: 0
> list_order_3_groups: 0
> list_order_4_groups: 0
> list_order_5_groups: 0
> list_order_6_groups: 0
> list_order_7_groups: 0
> list_order_8_groups: 0
> list_order_9_groups: 0
> list_order_10_groups: 0
> list_order_11_groups: 0
> list_order_12_groups: 0
> list_order_13_groups: 40
> fragment_size_tree:
> tree_min: 16384
> tree_max: 32768
> tree_nodes: 40
>
> Signed-off-by: Harshad Shirwadkar <[email protected]>

Reviewed-by: Andreas Dilger <[email protected]>

> ---
> fs/ext4/ext4.h | 1 +
> fs/ext4/mballoc.c | 86 +++++++++++++++++++++++++++++++++++++++++++++++
> fs/ext4/sysfs.c | 2 ++
> 3 files changed, 89 insertions(+)
>
> diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
> index 5930c8cb5159..f6a36a0e07c1 100644
> --- a/fs/ext4/ext4.h
> +++ b/fs/ext4/ext4.h
> @@ -2822,6 +2822,7 @@ int __init ext4_fc_init_dentry_cache(void);
>
> /* mballoc.c */
> extern const struct seq_operations ext4_mb_seq_groups_ops;
> +extern const struct seq_operations ext4_mb_seq_structs_summary_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);
> diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
> index fb53ec1e1d37..7ce1d1283fd9 100644
> --- a/fs/ext4/mballoc.c
> +++ b/fs/ext4/mballoc.c
> @@ -2945,6 +2945,92 @@ int ext4_seq_mb_stats_show(struct seq_file *seq, void *offset)
> return 0;
> }
>
> +static void *ext4_mb_seq_structs_summary_start(struct seq_file *seq, loff_t *pos)
> +{
> + struct super_block *sb = PDE_DATA(file_inode(seq->file));
> + unsigned long position;
> +
> + read_lock(&EXT4_SB(sb)->s_mb_rb_lock);
> +
> + if (*pos < 0 || *pos >= MB_NUM_ORDERS(sb) + 1)
> + return NULL;
> + position = *pos + 1;
> + return (void *) ((unsigned long) position);
> +}
> +
> +static void *ext4_mb_seq_structs_summary_next(struct seq_file *seq, void *v, loff_t *pos)
> +{
> + struct super_block *sb = PDE_DATA(file_inode(seq->file));
> + unsigned long position;
> +
> + ++*pos;
> + if (*pos < 0 || *pos >= MB_NUM_ORDERS(sb) + 1)
> + return NULL;
> + position = *pos + 1;
> + return (void *) ((unsigned long) position);
> +}
> +
> +static int ext4_mb_seq_structs_summary_show(struct seq_file *seq, void *v)
> +{
> + struct super_block *sb = PDE_DATA(file_inode(seq->file));
> + struct ext4_sb_info *sbi = EXT4_SB(sb);
> + unsigned long position = ((unsigned long) v);
> + struct ext4_group_info *grp;
> + struct rb_node *n;
> + unsigned int count, min, max;
> +
> + position--;
> + if (position >= MB_NUM_ORDERS(sb)) {
> + seq_puts(seq, "fragment_size_tree:\n");
> + n = rb_first(&sbi->s_mb_avg_fragment_size_root);
> + if (!n) {
> + seq_puts(seq, "\ttree_min: 0\n\ttree_max: 0\n\ttree_nodes: 0\n");
> + return 0;
> + }
> + grp = rb_entry(n, struct ext4_group_info, bb_avg_fragment_size_rb);
> + min = grp->bb_fragments ? grp->bb_free / grp->bb_fragments : 0;
> + count = 1;
> + while (rb_next(n)) {
> + count++;
> + n = rb_next(n);
> + }
> + grp = rb_entry(n, struct ext4_group_info, bb_avg_fragment_size_rb);
> + max = grp->bb_fragments ? grp->bb_free / grp->bb_fragments : 0;
> +
> + seq_printf(seq, "\ttree_min: %u\n\ttree_max: %u\n\ttree_nodes: %u\n",
> + min, max, count);
> + return 0;
> + }
> +
> + if (position == 0) {
> + seq_printf(seq, "optimize_scan: %d\n",
> + test_opt2(sb, MB_OPTIMIZE_SCAN) ? 1 : 0);
> + seq_puts(seq, "max_free_order_lists:\n");
> + }
> + count = 0;
> + list_for_each_entry(grp, &sbi->s_mb_largest_free_orders[position],
> + bb_largest_free_order_node)
> + count++;
> + seq_printf(seq, "\tlist_order_%u_groups: %u\n",
> + (unsigned int)position, count);
> +
> + return 0;
> +}
> +
> +static void ext4_mb_seq_structs_summary_stop(struct seq_file *seq, void *v)
> +{
> + struct super_block *sb = PDE_DATA(file_inode(seq->file));
> +
> + read_unlock(&EXT4_SB(sb)->s_mb_rb_lock);
> +}
> +
> +const struct seq_operations ext4_mb_seq_structs_summary_ops = {
> + .start = ext4_mb_seq_structs_summary_start,
> + .next = ext4_mb_seq_structs_summary_next,
> + .stop = ext4_mb_seq_structs_summary_stop,
> + .show = ext4_mb_seq_structs_summary_show,
> +};
> +
> static struct kmem_cache *get_groupinfo_cache(int blocksize_bits)
> {
> int cache_index = blocksize_bits - EXT4_MIN_BLOCK_LOG_SIZE;
> diff --git a/fs/ext4/sysfs.c b/fs/ext4/sysfs.c
> index 16b8a838f631..4a3b78684f83 100644
> --- a/fs/ext4/sysfs.c
> +++ b/fs/ext4/sysfs.c
> @@ -525,6 +525,8 @@ int ext4_register_sysfs(struct super_block *sb)
> &ext4_mb_seq_groups_ops, sb);
> proc_create_single_data("mb_stats", 0444, sbi->s_proc,
> ext4_seq_mb_stats_show, sb);
> + proc_create_seq_data("mb_structs_summary", 0444, sbi->s_proc,
> + &ext4_mb_seq_structs_summary_ops, sb);
> }
> return 0;
> }
> --
> 2.31.0.rc2.261.g7f71774620-goog
>


Cheers, Andreas






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