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| author | Theodore Ts'o <tytso@mit.edu> | 2013-02-09 06:59:22 +0400 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2013-02-09 06:59:22 +0400 |
| commit | 9924a92a8c217576bd2a2b1bbbb854462f1a00ae (patch) | |
| tree | 5c4eaee350e38cd2854fd6029da9f2a822ee184e /fs/ext4/ext4_jbd2.c | |
| parent | 722887ddc8982ff40e40b650fbca9ae1e56259bc (diff) | |
| download | linux-9924a92a8c217576bd2a2b1bbbb854462f1a00ae.tar.xz | |
ext4: pass context information to jbd2__journal_start()
So we can better understand what bits of ext4 are responsible for
long-running jbd2 handles, use jbd2__journal_start() so we can pass
context information for logging purposes.
The recommended way for finding the longer-running handles is:
T=/sys/kernel/debug/tracing
EVENT=$T/events/jbd2/jbd2_handle_stats
echo "interval > 5" > $EVENT/filter
echo 1 > $EVENT/enable
./run-my-fs-benchmark
cat $T/trace > /tmp/problem-handles
This will list handles that were active for longer than 20ms. Having
longer-running handles is bad, because a commit started at the wrong
time could stall for those 20+ milliseconds, which could delay an
fsync() or an O_SYNC operation. Here is an example line from the
trace file describing a handle which lived on for 311 jiffies, or over
1.2 seconds:
postmark-2917 [000] .... 196.435786: jbd2_handle_stats: dev 254,32
tid 570 type 2 line_no 2541 interval 311 sync 0 requested_blocks 1
dirtied_blocks 0
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Diffstat (limited to 'fs/ext4/ext4_jbd2.c')
| -rw-r--r-- | fs/ext4/ext4_jbd2.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/fs/ext4/ext4_jbd2.c b/fs/ext4/ext4_jbd2.c index 6f6114525535..7058975e3a55 100644 --- a/fs/ext4/ext4_jbd2.c +++ b/fs/ext4/ext4_jbd2.c @@ -38,7 +38,8 @@ static void ext4_put_nojournal(handle_t *handle) /* * Wrappers for jbd2_journal_start/end. */ -handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks) +handle_t *__ext4_journal_start_sb(struct super_block *sb, unsigned int line, + int type, int nblocks) { journal_t *journal; @@ -59,7 +60,7 @@ handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks) ext4_abort(sb, "Detected aborted journal"); return ERR_PTR(-EROFS); } - return jbd2_journal_start(journal, nblocks); + return jbd2__journal_start(journal, nblocks, GFP_NOFS, type, line); } int __ext4_journal_stop(const char *where, unsigned int line, handle_t *handle) |