Patchwork [3/4] jbd: yield the device queue when waiting for commits

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Submitter Jeff Moyer
Date April 14, 2010, 9:17 p.m.
Message ID <1271279826-30294-4-git-send-email-jmoyer@redhat.com>
Download mbox | patch
Permalink /patch/50192/
State New
Headers show

Comments

Jeff Moyer - April 14, 2010, 9:17 p.m.
This patch gets CFQ back in line with deadline for iozone runs, especially
those testing small files + fsync timings.

Signed-off-by: Jeff Moyer <jmoyer@redhat.com>
---
 fs/jbd/journal.c |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)

Patch

diff --git a/fs/jbd/journal.c b/fs/jbd/journal.c
index bd224ee..c1df4b2 100644
--- a/fs/jbd/journal.c
+++ b/fs/jbd/journal.c
@@ -36,6 +36,7 @@ 
 #include <linux/poison.h>
 #include <linux/proc_fs.h>
 #include <linux/debugfs.h>
+#include <linux/blkdev.h>
 
 #include <asm/uaccess.h>
 #include <asm/page.h>
@@ -549,6 +550,11 @@  int log_wait_commit(journal_t *journal, tid_t tid)
 	while (tid_gt(tid, journal->j_commit_sequence)) {
 		jbd_debug(1, "JBD: want %d, j_commit_sequence=%d\n",
 				  tid, journal->j_commit_sequence);
+		/*
+		 * Give up our I/O scheduler time slice to allow the journal
+		 * thread to issue I/O.
+		 */
+		blk_yield(journal->j_dev->bd_disk->queue);
 		wake_up(&journal->j_wait_commit);
 		spin_unlock(&journal->j_state_lock);
 		wait_event(journal->j_wait_done_commit,