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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/acl.c | |
| parent | 722887ddc8982ff40e40b650fbca9ae1e56259bc (diff) | |
| download | lwn-9924a92a8c217576bd2a2b1bbbb854462f1a00ae.tar.gz lwn-9924a92a8c217576bd2a2b1bbbb854462f1a00ae.zip | |
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/acl.c')
| -rw-r--r-- | fs/ext4/acl.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/fs/ext4/acl.c b/fs/ext4/acl.c index e6e0d988439b..406cf8bb12d5 100644 --- a/fs/ext4/acl.c +++ b/fs/ext4/acl.c @@ -324,7 +324,7 @@ ext4_acl_chmod(struct inode *inode) if (error) return error; retry: - handle = ext4_journal_start(inode, + handle = ext4_journal_start(inode, EXT4_HT_XATTR, EXT4_DATA_TRANS_BLOCKS(inode->i_sb)); if (IS_ERR(handle)) { error = PTR_ERR(handle); @@ -422,7 +422,8 @@ ext4_xattr_set_acl(struct dentry *dentry, const char *name, const void *value, acl = NULL; retry: - handle = ext4_journal_start(inode, EXT4_DATA_TRANS_BLOCKS(inode->i_sb)); + handle = ext4_journal_start(inode, EXT4_HT_XATTR, + EXT4_DATA_TRANS_BLOCKS(inode->i_sb)); if (IS_ERR(handle)) { error = PTR_ERR(handle); goto release_and_out; |