From 9ddf648f9c2a492cef4e41e31c50515a817d0562 Mon Sep 17 00:00:00 2001 From: Dennis Zhou Date: Thu, 2 Jan 2020 16:26:41 -0500 Subject: [PATCH] btrfs: keep track of discard reuse stats Keep track of how much we are discarding and how often we are reusing with async discard. The discard_*_bytes values don't need any special protection because the work item provides the single threaded access. Reviewed-by: Josef Bacik Signed-off-by: Dennis Zhou Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/ctree.h | 3 +++ fs/btrfs/discard.c | 5 +++++ fs/btrfs/free-space-cache.c | 14 ++++++++++++++ fs/btrfs/sysfs.c | 36 ++++++++++++++++++++++++++++++++++++ 4 files changed, 58 insertions(+) diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 486b9d1532eb..569931dd0ce5 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -473,6 +473,9 @@ struct btrfs_discard_ctl { unsigned long delay; u32 iops_limit; u32 kbps_limit; + u64 discard_extent_bytes; + u64 discard_bitmap_bytes; + atomic64_t discard_bytes_saved; }; /* delayed seq elem */ diff --git a/fs/btrfs/discard.c b/fs/btrfs/discard.c index 5af42e0317b7..40dcb5dcdc95 100644 --- a/fs/btrfs/discard.c +++ b/fs/btrfs/discard.c @@ -417,11 +417,13 @@ static void btrfs_discard_workfn(struct work_struct *work) block_group->discard_cursor, btrfs_block_group_end(block_group), minlen, maxlen, true); + discard_ctl->discard_bitmap_bytes += trimmed; } else { btrfs_trim_block_group_extents(block_group, &trimmed, block_group->discard_cursor, btrfs_block_group_end(block_group), minlen, true); + discard_ctl->discard_extent_bytes += trimmed; } discard_ctl->prev_discard = trimmed; @@ -626,6 +628,9 @@ void btrfs_discard_init(struct btrfs_fs_info *fs_info) discard_ctl->delay = BTRFS_DISCARD_MAX_DELAY_MSEC; discard_ctl->iops_limit = BTRFS_DISCARD_MAX_IOPS; discard_ctl->kbps_limit = 0; + discard_ctl->discard_extent_bytes = 0; + discard_ctl->discard_bitmap_bytes = 0; + atomic64_set(&discard_ctl->discard_bytes_saved, 0); } void btrfs_discard_cleanup(struct btrfs_fs_info *fs_info) diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c index a4340657b7f1..802e06d6303d 100644 --- a/fs/btrfs/free-space-cache.c +++ b/fs/btrfs/free-space-cache.c @@ -2842,6 +2842,8 @@ u64 btrfs_find_space_for_alloc(struct btrfs_block_group *block_group, u64 *max_extent_size) { struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl; + struct btrfs_discard_ctl *discard_ctl = + &block_group->fs_info->discard_ctl; struct btrfs_free_space *entry = NULL; u64 bytes_search = bytes + empty_size; u64 ret = 0; @@ -2858,6 +2860,10 @@ u64 btrfs_find_space_for_alloc(struct btrfs_block_group *block_group, ret = offset; if (entry->bitmap) { bitmap_clear_bits(ctl, entry, offset, bytes); + + if (!btrfs_free_space_trimmed(entry)) + atomic64_add(bytes, &discard_ctl->discard_bytes_saved); + if (!entry->bytes) free_bitmap(ctl, entry); } else { @@ -2866,6 +2872,9 @@ u64 btrfs_find_space_for_alloc(struct btrfs_block_group *block_group, align_gap = entry->offset; align_gap_trim_state = entry->trim_state; + if (!btrfs_free_space_trimmed(entry)) + atomic64_add(bytes, &discard_ctl->discard_bytes_saved); + entry->offset = offset + bytes; WARN_ON(entry->bytes < bytes + align_gap_len); @@ -2969,6 +2978,8 @@ u64 btrfs_alloc_from_cluster(struct btrfs_block_group *block_group, u64 min_start, u64 *max_extent_size) { struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl; + struct btrfs_discard_ctl *discard_ctl = + &block_group->fs_info->discard_ctl; struct btrfs_free_space *entry = NULL; struct rb_node *node; u64 ret = 0; @@ -3033,6 +3044,9 @@ out: spin_lock(&ctl->tree_lock); + if (!btrfs_free_space_trimmed(entry)) + atomic64_add(bytes, &discard_ctl->discard_bytes_saved); + ctl->free_space -= bytes; if (!entry->bitmap && !btrfs_free_space_trimmed(entry)) ctl->discardable_bytes[BTRFS_STAT_CURR] -= bytes; diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c index eac0155bf8c7..55e4ed1af29c 100644 --- a/fs/btrfs/sysfs.c +++ b/fs/btrfs/sysfs.c @@ -366,6 +366,39 @@ static ssize_t btrfs_discardable_extents_show(struct kobject *kobj, } BTRFS_ATTR(discard, discardable_extents, btrfs_discardable_extents_show); +static ssize_t btrfs_discard_bitmap_bytes_show(struct kobject *kobj, + struct kobj_attribute *a, + char *buf) +{ + struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj); + + return snprintf(buf, PAGE_SIZE, "%lld\n", + fs_info->discard_ctl.discard_bitmap_bytes); +} +BTRFS_ATTR(discard, discard_bitmap_bytes, btrfs_discard_bitmap_bytes_show); + +static ssize_t btrfs_discard_bytes_saved_show(struct kobject *kobj, + struct kobj_attribute *a, + char *buf) +{ + struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj); + + return snprintf(buf, PAGE_SIZE, "%lld\n", + atomic64_read(&fs_info->discard_ctl.discard_bytes_saved)); +} +BTRFS_ATTR(discard, discard_bytes_saved, btrfs_discard_bytes_saved_show); + +static ssize_t btrfs_discard_extent_bytes_show(struct kobject *kobj, + struct kobj_attribute *a, + char *buf) +{ + struct btrfs_fs_info *fs_info = discard_to_fs_info(kobj); + + return snprintf(buf, PAGE_SIZE, "%lld\n", + fs_info->discard_ctl.discard_extent_bytes); +} +BTRFS_ATTR(discard, discard_extent_bytes, btrfs_discard_extent_bytes_show); + static ssize_t btrfs_discard_iops_limit_show(struct kobject *kobj, struct kobj_attribute *a, char *buf) @@ -459,6 +492,9 @@ BTRFS_ATTR_RW(discard, max_discard_size, btrfs_discard_max_discard_size_show, static const struct attribute *discard_debug_attrs[] = { BTRFS_ATTR_PTR(discard, discardable_bytes), BTRFS_ATTR_PTR(discard, discardable_extents), + BTRFS_ATTR_PTR(discard, discard_bitmap_bytes), + BTRFS_ATTR_PTR(discard, discard_bytes_saved), + BTRFS_ATTR_PTR(discard, discard_extent_bytes), BTRFS_ATTR_PTR(discard, iops_limit), BTRFS_ATTR_PTR(discard, kbps_limit), BTRFS_ATTR_PTR(discard, max_discard_size), -- 2.30.2