[PATCHv2 00/10] ext4: Improve FC trace events

[Ritesh Harjani <riteshh@linux.ibm.com>]

Hello,

Please find the v2 of this patch series.

Note:- I still couldn't figure out how to expose EXT4_FC_REASON_MAX in patch-2
which (I think) might be (only) needed by trace-cmd or perf record for trace_ext4_fc_stats.
But it seems "cat /sys/kernel/debug/tracing/trace_pipe" gives the right output
for ext4_fc_stats trace event (as shown below).

So with above reasoning, do you think we should take these patches in?
And we can later see how to provide EXT4_FC_REASON_MAX definition available to
libtraceevent?

Either ways, please let me know your opinion around this.

<output of cat /sys/kernel/debug/tracing/trace_pipe> (shows FALLOC_RANGE:5)
=====================================================
jbd2/loop2-8-2219    [000] .....  1883.771539: ext4_fc_stats: dev 7,2 fc ineligible reasons:
XATTR:0, CROSS_RENAME:0, JOURNAL_FLAG_CHANGE:0, NO_MEM:0, SWAP_BOOT:0, RESIZE:0, RENAME_DIR:0, FALLOC_RANGE:5, INODE_JOURNAL_DATA:0 num_commits:22, ineligible: 4, numblks: 22


Changes since RFC
================
RFC -> v2
1. Added new patch-5 ("ext4: Return early for non-eligible fast_commit track events")
2. Removed a trace event in ext4_fc_track_template() (which was added in RFC)
   from patch-6 and added patch-7 to add the tid info in callers of
   ext4_fc_track_template(). (As per review comments from Jan)

Tested this with xfstests -g "quick"


[RFC]: https://lore.kernel.org/linux-ext4/cover.1645558375.git.riteshh@linux.ibm.com/

Ritesh Harjani (10):
  ext4: Remove unused enum EXT4_FC_COMMIT_FAILED
  ext4: Fix ext4_fc_stats trace point
  ext4: Convert ext4_fc_track_dentry type events to use event class
  ext4: Do not call FC trace event in ext4_fc_commit() if FS does not support FC
  ext4: Return early for non-eligible fast_commit track events
  ext4: Add new trace event in ext4_fc_cleanup
  ext4: Add transaction tid info in fc_track events
  ext4: Add commit_tid info in jbd debug log
  ext4: Add commit tid info in ext4_fc_commit_start/stop trace events
  ext4: Fix remaining two trace events to use same printk convention

 fs/ext4/fast_commit.c       |  95 ++++++++----
 fs/ext4/fast_commit.h       |   1 -
 include/trace/events/ext4.h | 297 +++++++++++++++++++++++-------------
 3 files changed, 257 insertions(+), 136 deletions(-)

Cc: Steven Rostedt <rostedt@goodmis.org>

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2.31.1