From: Eric Sandeen Date: Wed, 30 Jan 2013 05:39:28 +0000 (-0500) Subject: jbd2: don't wake kjournald unnecessarily X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=e7b04ac0;p=linux-beck.git 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 [tytso@mit.edu: reworked check to make it clearer] Signed-off-by: "Theodore Ts'o" --- 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,