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| author | Hitoshi Mitake <mitake.hitoshi@lab.ntt.co.jp> | 2015-11-07 01:31:59 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-11-07 02:50:42 +0100 |
| commit | 58497703837048ac501ce56056eb74b4361108fc (patch) | |
| tree | 57165f47606930e10f15d475e999ccdf9a273e7f /fs/nilfs2/segment.h | |
| parent | nilfs2: free unused dat file blocks during garbage collection (diff) | |
| download | linux-58497703837048ac501ce56056eb74b4361108fc.tar.xz linux-58497703837048ac501ce56056eb74b4361108fc.zip | |
nilfs2: add a tracepoint for tracking stage transition of segment construction
This patch adds a tracepoint for tracking stage transition of block
collection in segment construction. With the tracepoint, we can analysis
the behavior of segment construction in depth. It would be useful for
bottleneck detection and debugging, etc.
The tracepoint is created with the standard trace API of linux (like ext3,
ext4, f2fs and btrfs). So we can analysis with existing tools easily. Of
course, more detailed analysis will be possible if we can create nilfs
specific analysis tools.
Below is an example of event dump with Brendan Gregg's perf-tools
(https://github.com/brendangregg/perf-tools). Time consumption between
each stage can be obtained.
$ sudo bin/tpoint nilfs2:nilfs2_collection_stage_transition
Tracing nilfs2:nilfs2_collection_stage_transition. Ctrl-C to end.
segctord-14875 [003] ...1 28311.067794: nilfs2_collection_stage_transition: sci = ffff8800ce6de000 stage = ST_INIT
segctord-14875 [003] ...1 28311.068139: nilfs2_collection_stage_transition: sci = ffff8800ce6de000 stage = ST_GC
segctord-14875 [003] ...1 28311.068139: nilfs2_collection_stage_transition: sci = ffff8800ce6de000 stage = ST_FILE
segctord-14875 [003] ...1 28311.068486: nilfs2_collection_stage_transition: sci = ffff8800ce6de000 stage = ST_IFILE
segctord-14875 [003] ...1 28311.068540: nilfs2_collection_stage_transition: sci = ffff8800ce6de000 stage = ST_CPFILE
segctord-14875 [003] ...1 28311.068561: nilfs2_collection_stage_transition: sci = ffff8800ce6de000 stage = ST_SUFILE
segctord-14875 [003] ...1 28311.068565: nilfs2_collection_stage_transition: sci = ffff8800ce6de000 stage = ST_DAT
segctord-14875 [003] ...1 28311.068573: nilfs2_collection_stage_transition: sci = ffff8800ce6de000 stage = ST_SR
segctord-14875 [003] ...1 28311.068574: nilfs2_collection_stage_transition: sci = ffff8800ce6de000 stage = ST_DONE
For capturing transition correctly, this patch adds wrappers for the
member scnt of nilfs_cstage. With this change, every transition of the
stage can produce trace event in a correct manner.
Signed-off-by: Hitoshi Mitake <mitake.hitoshi@lab.ntt.co.jp>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/nilfs2/segment.h')
| -rw-r--r-- | fs/nilfs2/segment.h | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/fs/nilfs2/segment.h b/fs/nilfs2/segment.h index a48d6de1e02c..0408b9b2814b 100644 --- a/fs/nilfs2/segment.h +++ b/fs/nilfs2/segment.h @@ -67,7 +67,8 @@ struct nilfs_recovery_info { /** * struct nilfs_cstage - Context of collection stage - * @scnt: Stage count + * @scnt: Stage count, must be accessed via wrappers: + * nilfs_sc_cstage_inc(), nilfs_sc_cstage_set(), nilfs_sc_cstage_get() * @flags: State flags * @dirty_file_ptr: Pointer on dirty_files list, or inode of a target file * @gc_inode_ptr: Pointer on the list of gc-inodes |