Patchwork [4/6] jbd: use WRITE_SYNC for journal I/O

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Submitter Jeff Moyer
Date July 2, 2010, 7:58 p.m.
Message ID <>
Download mbox | patch
Permalink /patch/57767/
State New
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Jeff Moyer - July 2, 2010, 7:58 p.m.
In my fsync testing, journal I/O most definitely was sync I/O, since
another process was blocked waiting for the results.  By marking all
journal I/O as WRITE_SYNC, I can get better performance with CFQ.

If there is a way to mark this only for cases where it is blocking progress
in a dependent process, then that would be preferrable.  Is there such a
means for determining and flagging this?


Signed-off-by: Jeff Moyer <>
 fs/jbd/commit.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)


diff --git a/fs/jbd/commit.c b/fs/jbd/commit.c
index 28a9dda..d97a0c6 100644
--- a/fs/jbd/commit.c
+++ b/fs/jbd/commit.c
@@ -317,7 +317,7 @@  void journal_commit_transaction(journal_t *journal)
 	int first_tag = 0;
 	int tag_flag;
 	int i;
-	int write_op = WRITE;
+	int write_op = WRITE_SYNC;
 	 * First job: lock down the current transaction and wait for