linux-stable.git/fs/ext4/fast_commit.c, branch v5.19

ext4: remove unnecessary conditionals

2022-05-13T20:27:24+00:00

iput() has already handled null and non-null parameter, so it is no
need to use if().

Reported-by: Zeal Robot 
Signed-off-by: Lv Ruyi 
Link: https://lore.kernel.org/r/20220411032337.2517465-1-lv.ruyi@zte.com.cn
Signed-off-by: Theodore Ts'o

ext4: remove unnecessary type castings

2022-05-11T19:19:06+00:00

remove unnecessary void* type castings.

Signed-off-by: Yu Zhe 
Link: https://lore.kernel.org/r/20220401081321.73735-1-yuzhe@nfschina.com
Signed-off-by: Theodore Ts'o

ext4: add commit tid info in ext4_fc_commit_start/stop trace events

2022-03-15T21:45:36+00:00

This adds commit_tid info in ext4_fc_commit_start/stop which is helpful
in debugging fast_commit issues.

For e.g. issues where due to jbd2 journal full commit, FC miss to commit
updates to a file.

Also improves TP_prink format string i.e. all ext4 and jbd2 trace events
starts with "dev MAjOR,MINOR". Let's follow the same convention while we
are still at it.

Signed-off-by: Ritesh Harjani 
Reviewed-by: Jan Kara 
Reviewed-by: Harshad Shirwadkar 
Link: https://lore.kernel.org/r/ebcd6b9ab5b718db30f90854497886801ce38c63.1647057583.git.riteshh@linux.ibm.com
Signed-off-by: Theodore Ts'o

ext4: add commit_tid info in jbd debug log

2022-03-15T21:45:36+00:00

This adds commit_tid argument in ext4_fc_update_stats()
so that we can add this information too in jbd_debug logs.
This is also required in a later patch to pass the commit_tid info in
ext4_fc_commit_start/stop() trace events.

Signed-off-by: Ritesh Harjani 
Reviewed-by: Jan Kara 
Reviewed-by: Harshad Shirwadkar 
Link: https://lore.kernel.org/r/dabda3f2919a60e01887e798bf5915216b451733.1647057583.git.riteshh@linux.ibm.com
Signed-off-by: Theodore Ts'o

ext4: add transaction tid info in fc_track events

2022-03-15T21:45:36+00:00

This patch adds the transaction & inode tid info in trace events for
callers of ext4_fc_track_template(). This is helpful in debugging race
conditions where an inode could belong to two different transaction tids.
It also fixes the checkpatch warnings which says use tabs instead of
spaces.

Signed-off-by: Ritesh Harjani 
Link: https://lore.kernel.org/r/c203c09dc11bb372803c430f621f25a4b8c2c8b4.1647057583.git.riteshh@linux.ibm.com
Signed-off-by: Theodore Ts'o

ext4: add new trace event in ext4_fc_cleanup

2022-03-15T21:45:36+00:00

This adds a new trace event in ext4_fc_cleanup() which is helpful in debugging
some fast_commit issues.

Signed-off-by: Ritesh Harjani 
Link: https://lore.kernel.org/r/794cdb1d5d3622f3f80d30c222ff6652ea68c375.1647057583.git.riteshh@linux.ibm.com
Signed-off-by: Theodore Ts'o

ext4: return early for non-eligible fast_commit track events

2022-03-15T21:44:46+00:00

Currently ext4_fc_track_template() checks, whether the trace event
path belongs to replay or does sb has ineligible set, if yes it simply
returns. This patch pulls those checks before calling
ext4_fc_track_template() in the callers of ext4_fc_track_template().

[ Add checks to ext4_rename() which calls the __ext4_fc_track_*()
  functions directly. -- TYT ]

Signed-off-by: Ritesh Harjani 
Link: https://lore.kernel.org/r/3cd025d9c490218a92e6d8fb30b6123e693373e3.1647057583.git.riteshh@linux.ibm.com
Signed-off-by: Theodore Ts'o

ext4: do not call FC trace event in ext4_fc_commit() if FS does not support FC

2022-03-13T02:26:08+00:00

This just puts trace_ext4_fc_commit_start(sb) & ktime_get()
for measuring FC commit time, after the check of whether sb
supports JOURNAL_FAST_COMMIT or not.

Signed-off-by: Ritesh Harjani 
Reviewed-by: Harshad Shirwadkar 
Reviewed-by: Jan Kara 
Link: https://lore.kernel.org/r/d53cf3e535924ec0a1eb41a560e96561b0727e7a.1647057583.git.riteshh@linux.ibm.com
Signed-off-by: Theodore Ts'o

ext4: improve fast_commit performance and scalability

2022-03-03T04:11:15+00:00

Currently ext4_fc_commit_dentry_updates() is of quadratic time
complexity, which is causing performance bottlenecks with high
threads/file/dir count with fs_mark.

This patch makes commit dentry updates (and hence ext4_fc_commit()) path
to linear time complexity. Hence improves the performance of workloads
which does fsync on multiple threads/open files one-by-one.

Absolute numbers in avg file creates per sec (from fs_mark in 1K order)
=======================================================================
no.     Order   without-patch(K)   with-patch(K)   Diff(%)
1       1        16.90              17.51           +3.60
2       2,2      32.08              31.80           -0.87
3       3,3      53.97              55.01           +1.92
4       4,4      78.94              76.90           -2.58
5       5,5      95.82              95.37           -0.46
6       6,6      87.92              103.38          +17.58
7       6,10      0.73              126.13          +17178.08
8       6,14      2.33              143.19          +6045.49

workload type
==============
For e.g. 7th row order of 6,10 (2^6 == 64 && 2^10 == 1024)
echo /run/riteshh/mnt/{1..64} |sed -E 's/[[:space:]]+/ -d /g' \
  | xargs -I {} bash -c "sudo fs_mark -L 100 -D 1024 -n 1024 -s0 -S5 -d {}"

Perf profile
(w/o patches)
=============================
87.15%  [kernel]  [k] ext4_fc_commit           --> Heavy contention/bottleneck
 1.98%  [kernel]  [k] perf_event_interrupt
 0.96%  [kernel]  [k] power_pmu_enable
 0.91%  [kernel]  [k] update_sd_lb_stats.constprop.0
 0.67%  [kernel]  [k] ktime_get

Signed-off-by: Ritesh Harjani 
Reviewed-by: Harshad Shirwadkar 
Link: https://lore.kernel.org/r/930f35d4fd5f83e2673c868781d9ebf15e91bf4e.1645426817.git.riteshh@linux.ibm.com
Signed-off-by: Theodore Ts'o

ext4: use in_range() for range checking in ext4_fc_replay_check_excluded

2022-02-26T02:34:56+00:00

Instead of open coding it, use in_range() function instead.

Signed-off-by: Ritesh Harjani 
Reviewed-by: Jan Kara 
Link: https://lore.kernel.org/r/8e5526ef14150778871ac7c937c8993c6a09cd3e.1644992610.git.riteshh@linux.ibm.com
Signed-off-by: Theodore Ts'o