From 900a1ba42330d2fba56c9944820debad557c818f Mon Sep 17 00:00:00 2001 From: Dennis Zhou Date: Fri, 13 Dec 2019 16:22:21 -0800 Subject: [PATCH] btrfs: keep track of discardable_bytes for async discard Keep track of this metric so that we can understand how ahead or behind we are in discarding rate. This uses the same accounting method as discardable_extents, deltas between previous/current values and propagating them up. Signed-off-by: Dennis Zhou Reviewed-by: David Sterba [ update changelog ] Signed-off-by: David Sterba --- fs/btrfs/ctree.h | 1 + fs/btrfs/discard.c | 10 +++++++++ fs/btrfs/free-space-cache.c | 41 +++++++++++++++++++++++++++++-------- fs/btrfs/free-space-cache.h | 1 + fs/btrfs/sysfs.c | 12 +++++++++++ 5 files changed, 56 insertions(+), 9 deletions(-) diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 533c5ea0e8c07..7c1c236d13ae6 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -467,6 +467,7 @@ struct btrfs_discard_ctl { struct btrfs_block_group *block_group; struct list_head discard_list[BTRFS_NR_DISCARD_LISTS]; atomic_t discardable_extents; + atomic64_t discardable_bytes; }; /* delayed seq elem */ diff --git a/fs/btrfs/discard.c b/fs/btrfs/discard.c index 99663641abf4f..62298a438fa5d 100644 --- a/fs/btrfs/discard.c +++ b/fs/btrfs/discard.c @@ -356,6 +356,7 @@ void btrfs_discard_update_discardable(struct btrfs_block_group *block_group, { struct btrfs_discard_ctl *discard_ctl; s32 extents_delta; + s64 bytes_delta; if (!block_group || !btrfs_test_opt(block_group->fs_info, DISCARD_ASYNC)) return; @@ -369,6 +370,14 @@ void btrfs_discard_update_discardable(struct btrfs_block_group *block_group, ctl->discardable_extents[BTRFS_STAT_PREV] = ctl->discardable_extents[BTRFS_STAT_CURR]; } + + bytes_delta = ctl->discardable_bytes[BTRFS_STAT_CURR] - + ctl->discardable_bytes[BTRFS_STAT_PREV]; + if (bytes_delta) { + atomic64_add(bytes_delta, &discard_ctl->discardable_bytes); + ctl->discardable_bytes[BTRFS_STAT_PREV] = + ctl->discardable_bytes[BTRFS_STAT_CURR]; + } } /** @@ -454,6 +463,7 @@ void btrfs_discard_init(struct btrfs_fs_info *fs_info) INIT_LIST_HEAD(&discard_ctl->discard_list[i]); atomic_set(&discard_ctl->discardable_extents, 0); + atomic64_set(&discard_ctl->discardable_bytes, 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 ed97d082feaca..40fb918a82f49 100644 --- a/fs/btrfs/free-space-cache.c +++ b/fs/btrfs/free-space-cache.c @@ -819,9 +819,11 @@ static int __load_free_space_cache(struct btrfs_root *root, struct inode *inode, if (ret) goto free_cache; e->bitmap_extents = count_bitmap_extents(ctl, e); - if (!btrfs_free_space_trimmed(e)) + if (!btrfs_free_space_trimmed(e)) { ctl->discardable_extents[BTRFS_STAT_CURR] += e->bitmap_extents; + ctl->discardable_bytes[BTRFS_STAT_CURR] += e->bytes; + } } io_ctl_drop_pages(&io_ctl); @@ -1643,8 +1645,10 @@ __unlink_free_space(struct btrfs_free_space_ctl *ctl, rb_erase(&info->offset_index, &ctl->free_space_offset); ctl->free_extents--; - if (!info->bitmap && !btrfs_free_space_trimmed(info)) + if (!info->bitmap && !btrfs_free_space_trimmed(info)) { ctl->discardable_extents[BTRFS_STAT_CURR]--; + ctl->discardable_bytes[BTRFS_STAT_CURR] -= info->bytes; + } } static void unlink_free_space(struct btrfs_free_space_ctl *ctl, @@ -1665,8 +1669,10 @@ static int link_free_space(struct btrfs_free_space_ctl *ctl, if (ret) return ret; - if (!info->bitmap && !btrfs_free_space_trimmed(info)) + if (!info->bitmap && !btrfs_free_space_trimmed(info)) { ctl->discardable_extents[BTRFS_STAT_CURR]++; + ctl->discardable_bytes[BTRFS_STAT_CURR] += info->bytes; + } ctl->free_space += info->bytes; ctl->free_extents++; @@ -1745,8 +1751,10 @@ static inline void __bitmap_clear_bits(struct btrfs_free_space_ctl *ctl, extent_delta++; info->bitmap_extents += extent_delta; - if (!btrfs_free_space_trimmed(info)) + if (!btrfs_free_space_trimmed(info)) { ctl->discardable_extents[BTRFS_STAT_CURR] += extent_delta; + ctl->discardable_bytes[BTRFS_STAT_CURR] -= bytes; + } } static void bitmap_clear_bits(struct btrfs_free_space_ctl *ctl, @@ -1781,8 +1789,10 @@ static void bitmap_set_bits(struct btrfs_free_space_ctl *ctl, extent_delta--; info->bitmap_extents += extent_delta; - if (!btrfs_free_space_trimmed(info)) + if (!btrfs_free_space_trimmed(info)) { ctl->discardable_extents[BTRFS_STAT_CURR] += extent_delta; + ctl->discardable_bytes[BTRFS_STAT_CURR] += bytes; + } } /* @@ -2053,9 +2063,11 @@ static u64 add_bytes_to_bitmap(struct btrfs_free_space_ctl *ctl, * whole bitmap untrimmed if at any point we add untrimmed regions. */ if (trim_state == BTRFS_TRIM_STATE_UNTRIMMED) { - if (btrfs_free_space_trimmed(info)) + if (btrfs_free_space_trimmed(info)) { ctl->discardable_extents[BTRFS_STAT_CURR] += info->bitmap_extents; + ctl->discardable_bytes[BTRFS_STAT_CURR] += info->bytes; + } info->trim_state = BTRFS_TRIM_STATE_UNTRIMMED; } @@ -2713,15 +2725,21 @@ __btrfs_return_cluster_to_free_space( bitmap = (entry->bitmap != NULL); if (!bitmap) { /* Merging treats extents as if they were new */ - if (!btrfs_free_space_trimmed(entry)) + if (!btrfs_free_space_trimmed(entry)) { ctl->discardable_extents[BTRFS_STAT_CURR]--; + ctl->discardable_bytes[BTRFS_STAT_CURR] -= + entry->bytes; + } try_merge_free_space(ctl, entry, false); steal_from_bitmap(ctl, entry, false); /* As we insert directly, update these statistics */ - if (!btrfs_free_space_trimmed(entry)) + if (!btrfs_free_space_trimmed(entry)) { ctl->discardable_extents[BTRFS_STAT_CURR]++; + ctl->discardable_bytes[BTRFS_STAT_CURR] += + entry->bytes; + } } tree_insert_offset(&ctl->free_space_offset, entry->offset, &entry->offset_index, bitmap); @@ -3011,6 +3029,8 @@ out: spin_lock(&ctl->tree_lock); ctl->free_space -= bytes; + if (!entry->bitmap && !btrfs_free_space_trimmed(entry)) + ctl->discardable_bytes[BTRFS_STAT_CURR] -= bytes; if (entry->bytes == 0) { ctl->free_extents--; if (entry->bitmap) { @@ -3515,9 +3535,11 @@ static void reset_trimming_bitmap(struct btrfs_free_space_ctl *ctl, u64 offset) spin_lock(&ctl->tree_lock); entry = tree_search_offset(ctl, offset, 1, 0); if (entry) { - if (btrfs_free_space_trimmed(entry)) + if (btrfs_free_space_trimmed(entry)) { ctl->discardable_extents[BTRFS_STAT_CURR] += entry->bitmap_extents; + ctl->discardable_bytes[BTRFS_STAT_CURR] += entry->bytes; + } entry->trim_state = BTRFS_TRIM_STATE_UNTRIMMED; } @@ -3531,6 +3553,7 @@ static void end_trimming_bitmap(struct btrfs_free_space_ctl *ctl, entry->trim_state = BTRFS_TRIM_STATE_TRIMMED; ctl->discardable_extents[BTRFS_STAT_CURR] -= entry->bitmap_extents; + ctl->discardable_bytes[BTRFS_STAT_CURR] -= entry->bytes; } } diff --git a/fs/btrfs/free-space-cache.h b/fs/btrfs/free-space-cache.h index bd1e7a5422718..5018190a49a34 100644 --- a/fs/btrfs/free-space-cache.h +++ b/fs/btrfs/free-space-cache.h @@ -52,6 +52,7 @@ struct btrfs_free_space_ctl { int unit; u64 start; s32 discardable_extents[BTRFS_STAT_NR_ENTRIES]; + s64 discardable_bytes[BTRFS_STAT_NR_ENTRIES]; const struct btrfs_free_space_op *op; void *private; struct mutex cache_writeout_mutex; diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c index 0ac122c670650..ce1da3fcd6c98 100644 --- a/fs/btrfs/sysfs.c +++ b/fs/btrfs/sysfs.c @@ -344,6 +344,17 @@ static const struct attribute_group btrfs_static_feature_attr_group = { */ #define discard_to_fs_info(_kobj) to_fs_info((_kobj)->parent->parent) +static ssize_t btrfs_discardable_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", + atomic64_read(&fs_info->discard_ctl.discardable_bytes)); +} +BTRFS_ATTR(discard, discardable_bytes, btrfs_discardable_bytes_show); + static ssize_t btrfs_discardable_extents_show(struct kobject *kobj, struct kobj_attribute *a, char *buf) @@ -356,6 +367,7 @@ static ssize_t btrfs_discardable_extents_show(struct kobject *kobj, BTRFS_ATTR(discard, discardable_extents, btrfs_discardable_extents_show); static const struct attribute *discard_debug_attrs[] = { + BTRFS_ATTR_PTR(discard, discardable_bytes), BTRFS_ATTR_PTR(discard, discardable_extents), NULL, }; -- 2.39.5