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| author | Theodore Ts'o <tytso@mit.edu> | 2013-02-08 21:59:22 -0500 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2013-02-08 21:59:22 -0500 |
| commit | 9924a92a8c217576bd2a2b1bbbb854462f1a00ae (patch) | |
| tree | 5c4eaee350e38cd2854fd6029da9f2a822ee184e /fs/ext4/indirect.c | |
| parent | 722887ddc8982ff40e40b650fbca9ae1e56259bc (diff) | |
| download | linux-9924a92a8c217576bd2a2b1bbbb854462f1a00ae.tar.bz2 | |
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/indirect.c')
| -rw-r--r-- | fs/ext4/indirect.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/fs/ext4/indirect.c b/fs/ext4/indirect.c index 193281098fb6..c541ab8b64dd 100644 --- a/fs/ext4/indirect.c +++ b/fs/ext4/indirect.c @@ -791,7 +791,7 @@ ssize_t ext4_ind_direct_IO(int rw, struct kiocb *iocb, if (final_size > inode->i_size) { /* Credits for sb + inode write */ - handle = ext4_journal_start(inode, 2); + handle = ext4_journal_start(inode, EXT4_HT_INODE, 2); if (IS_ERR(handle)) { ret = PTR_ERR(handle); goto out; @@ -851,7 +851,7 @@ locked: int err; /* Credits for sb + inode write */ - handle = ext4_journal_start(inode, 2); + handle = ext4_journal_start(inode, EXT4_HT_INODE, 2); if (IS_ERR(handle)) { /* This is really bad luck. We've written the data * but cannot extend i_size. Bail out and pretend @@ -950,7 +950,8 @@ static handle_t *start_transaction(struct inode *inode) { handle_t *result; - result = ext4_journal_start(inode, ext4_blocks_for_truncate(inode)); + result = ext4_journal_start(inode, EXT4_HT_TRUNCATE, + ext4_blocks_for_truncate(inode)); if (!IS_ERR(result)) return result; |