From: Eric Sandeen Date: Tue, 18 Dec 2012 17:03:57 +0000 (-0600) Subject: jbd: don't wake kjournald unnecessarily X-Git-Tag: firefly_0821_release~3680^2~1253^2~1 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=7e2fb2d7e6a3094473f101ae33dd6431ae6d2ed1;p=firefly-linux-kernel-4.4.55.git jbd: 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 commit has already been requested for commit. commit d9b0193 "jbd: 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 Signed-off-by: Jan Kara --- diff --git a/fs/jbd/journal.c b/fs/jbd/journal.c index a2862339323b..81cc7eaff863 100644 --- a/fs/jbd/journal.c +++ b/fs/jbd/journal.c @@ -446,7 +446,8 @@ int __log_start_commit(journal_t *journal, tid_t target) * currently running transaction (if it exists). Otherwise, * the target tid must be an old one. */ - if (journal->j_running_transaction && + if (journal->j_commit_request != target && + journal->j_running_transaction && journal->j_running_transaction->t_tid == target) { /* * We want a new commit: OK, mark the request and wakeup the