| Message ID | 20200728014249.35532-1-wqu@suse.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | btrfs: trace: output proper root owner for trace_find_free_extent() | expand |
On Tue, Jul 28, 2020 at 09:42:49AM +0800, Qu Wenruo wrote: > The current trace event always output result like this: > > find_free_extent: root=2(EXTENT_TREE) len=16384 empty_size=0 flags=4(METADATA) > find_free_extent: root=2(EXTENT_TREE) len=16384 empty_size=0 flags=4(METADATA) > find_free_extent: root=2(EXTENT_TREE) len=8192 empty_size=0 flags=1(DATA) > find_free_extent: root=2(EXTENT_TREE) len=8192 empty_size=0 flags=1(DATA) > find_free_extent: root=2(EXTENT_TREE) len=4096 empty_size=0 flags=1(DATA) > find_free_extent: root=2(EXTENT_TREE) len=4096 empty_size=0 flags=1(DATA) > > It's driving me crazy, as it's saying we're allocating data extent for > EXTENT tree, which is not even possible. > > It's because we always use EXTENT tree as the owner for > trace_find_free_extent() without using the @root from > btrfs_reserve_extent(). > > This patch will change the parameter to use proper @root for > trace_find_free_extent() to make life a little easier. > > Now it looks much better: > find_free_extent: root=5(FS_TREE) len=16384 empty_size=0 flags=36(METADATA|DUP) > find_free_extent: root=5(FS_TREE) len=8192 empty_size=0 flags=1(DATA) > find_free_extent: root=5(FS_TREE) len=16384 empty_size=0 flags=1(DATA) > find_free_extent: root=5(FS_TREE) len=4096 empty_size=0 flags=1(DATA) > find_free_extent: root=5(FS_TREE) len=8192 empty_size=0 flags=1(DATA) > find_free_extent: root=5(FS_TREE) len=16384 empty_size=0 flags=36(METADATA|DUP) > find_free_extent: root=7(CSUM_TREE) len=16384 empty_size=0 flags=36(METADATA|DUP) > find_free_extent: root=2(EXTENT_TREE) len=16384 empty_size=0 flags=36(METADATA|DUP) > find_free_extent: root=1(ROOT_TREE) len=16384 empty_size=0 flags=36(METADATA|DUP) > > Reported-by: Hans van Kranenburg <hans@knorrie.org> > Signed-off-by: Qu Wenruo <wqu@suse.com> Thanks, added to misc-next, with some changelog adjustments.
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 61ede335f6c3..fa7d83051587 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -3913,11 +3913,12 @@ static int prepare_allocation(struct btrfs_fs_info *fs_info, * |- Push harder to find free extents * |- If not found, re-iterate all block groups */ -static noinline int find_free_extent(struct btrfs_fs_info *fs_info, +static noinline int find_free_extent(struct btrfs_root *root, u64 ram_bytes, u64 num_bytes, u64 empty_size, u64 hint_byte_orig, struct btrfs_key *ins, u64 flags, int delalloc) { + struct btrfs_fs_info *fs_info = root->fs_info; int ret = 0; int cache_block_group_error = 0; struct btrfs_block_group *block_group = NULL; @@ -3949,7 +3950,7 @@ static noinline int find_free_extent(struct btrfs_fs_info *fs_info, ins->objectid = 0; ins->offset = 0; - trace_find_free_extent(fs_info, num_bytes, empty_size, flags); + trace_find_free_extent(root, num_bytes, empty_size, flags); space_info = btrfs_find_space_info(fs_info, flags); if (!space_info) { @@ -4198,7 +4199,7 @@ int btrfs_reserve_extent(struct btrfs_root *root, u64 ram_bytes, flags = get_alloc_profile_by_root(root, is_data); again: WARN_ON(num_bytes < fs_info->sectorsize); - ret = find_free_extent(fs_info, ram_bytes, num_bytes, empty_size, + ret = find_free_extent(root, ram_bytes, num_bytes, empty_size, hint_byte, ins, flags, delalloc); if (!ret && !is_data) { btrfs_dec_block_group_reservations(fs_info, ins->objectid); diff --git a/include/trace/events/btrfs.h b/include/trace/events/btrfs.h index 863335ecb7e8..b9241836d4f7 100644 --- a/include/trace/events/btrfs.h +++ b/include/trace/events/btrfs.h @@ -1176,25 +1176,27 @@ DEFINE_EVENT(btrfs__reserved_extent, btrfs_reserved_extent_free, TRACE_EVENT(find_free_extent, - TP_PROTO(const struct btrfs_fs_info *fs_info, u64 num_bytes, + TP_PROTO(const struct btrfs_root *root, u64 num_bytes, u64 empty_size, u64 data), - TP_ARGS(fs_info, num_bytes, empty_size, data), + TP_ARGS(root, num_bytes, empty_size, data), TP_STRUCT__entry_btrfs( + __field( u64, root_objectid ) __field( u64, num_bytes ) __field( u64, empty_size ) __field( u64, data ) ), - TP_fast_assign_btrfs(fs_info, + TP_fast_assign_btrfs(root->fs_info, + __entry->root_objectid = root->root_key.objectid; __entry->num_bytes = num_bytes; __entry->empty_size = empty_size; __entry->data = data; ), TP_printk_btrfs("root=%llu(%s) len=%llu empty_size=%llu flags=%llu(%s)", - show_root_type(BTRFS_EXTENT_TREE_OBJECTID), + show_root_type(__entry->root_objectid), __entry->num_bytes, __entry->empty_size, __entry->data, __print_flags((unsigned long)__entry->data, "|", BTRFS_GROUP_FLAGS))
The current trace event always output result like this: find_free_extent: root=2(EXTENT_TREE) len=16384 empty_size=0 flags=4(METADATA) find_free_extent: root=2(EXTENT_TREE) len=16384 empty_size=0 flags=4(METADATA) find_free_extent: root=2(EXTENT_TREE) len=8192 empty_size=0 flags=1(DATA) find_free_extent: root=2(EXTENT_TREE) len=8192 empty_size=0 flags=1(DATA) find_free_extent: root=2(EXTENT_TREE) len=4096 empty_size=0 flags=1(DATA) find_free_extent: root=2(EXTENT_TREE) len=4096 empty_size=0 flags=1(DATA) It's driving me crazy, as it's saying we're allocating data extent for EXTENT tree, which is not even possible. It's because we always use EXTENT tree as the owner for trace_find_free_extent() without using the @root from btrfs_reserve_extent(). This patch will change the parameter to use proper @root for trace_find_free_extent() to make life a little easier. Now it looks much better: find_free_extent: root=5(FS_TREE) len=16384 empty_size=0 flags=36(METADATA|DUP) find_free_extent: root=5(FS_TREE) len=8192 empty_size=0 flags=1(DATA) find_free_extent: root=5(FS_TREE) len=16384 empty_size=0 flags=1(DATA) find_free_extent: root=5(FS_TREE) len=4096 empty_size=0 flags=1(DATA) find_free_extent: root=5(FS_TREE) len=8192 empty_size=0 flags=1(DATA) find_free_extent: root=5(FS_TREE) len=16384 empty_size=0 flags=36(METADATA|DUP) find_free_extent: root=7(CSUM_TREE) len=16384 empty_size=0 flags=36(METADATA|DUP) find_free_extent: root=2(EXTENT_TREE) len=16384 empty_size=0 flags=36(METADATA|DUP) find_free_extent: root=1(ROOT_TREE) len=16384 empty_size=0 flags=36(METADATA|DUP) Reported-by: Hans van Kranenburg <hans@knorrie.org> Signed-off-by: Qu Wenruo <wqu@suse.com> --- fs/btrfs/extent-tree.c | 7 ++++--- include/trace/events/btrfs.h | 10 ++++++---- 2 files changed, 10 insertions(+), 7 deletions(-)