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| author | Eric Sandeen <sandeen@redhat.com> | 2013-01-30 06:39:28 +0100 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2013-01-30 06:39:28 +0100 |
| commit | e7b04ac00ee273cb2c699ed14139fc072add4097 (patch) | |
| tree | 07a7b90bec97ee73f0a7732e6ac1121f81264ea9 | |
| parent | ext4: fix possible use-after-free with AIO (diff) | |
| download | linux-e7b04ac00ee273cb2c699ed14139fc072add4097.tar.xz linux-e7b04ac00ee273cb2c699ed14139fc072add4097.zip | |
jbd2: don't wake kjournald unnecessarily
Don't send an extra wakeup to kjournald in the case where we
already have the proper target in j_commit_request, i.e. that
transaction has already been requested for commit.
commit deeeaf13 "jbd2: fix fsync() tid wraparound bug" changed
the logic leading to a wakeup, but it caused some extra wakeups
which were found to lead to a measurable performance regression.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
[tytso@mit.edu: reworked check to make it clearer]
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
| -rw-r--r-- | fs/jbd2/journal.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c index dbf41f9452db..1a80e3146a59 100644 --- a/fs/jbd2/journal.c +++ b/fs/jbd2/journal.c @@ -513,6 +513,10 @@ int __jbd2_log_space_left(journal_t *journal) */ int __jbd2_log_start_commit(journal_t *journal, tid_t target) { + /* Return if the txn has already requested to be committed */ + if (journal->j_commit_request == target) + return 0; + /* * The only transaction we can possibly wait upon is the * currently running transaction (if it exists). Otherwise, |