GFS2: Sort the ordered write list

This patch sorts the ordered write list for GFS2 writes. This increases the throughput for simultaneous writes. For example, if you have ten processes, all doing: dd if=/dev/zero of=/mnt/gfs2/fileX on different files, the throughput will be much better. Signed-off-by: Bob Peterson <[email protected]> Signed-off-by: Steven Whitehouse <[email protected]>
hanmiltonxing · Feb 28, 2012 · 4a36d08 · 4a36d08
1 parent 66fc061
commit 4a36d08
Showing 1 changed file with 16 additions and 0 deletions.
diff --git a/fs/gfs2/log.c b/fs/gfs2/log.c
@@ -19,6 +19,7 @@
 #include <linux/freezer.h>
 #include <linux/bio.h>
 #include <linux/writeback.h>
+#include <linux/list_sort.h>
 
 #include "gfs2.h"
 #include "incore.h"
@@ -566,13 +567,28 @@ static void log_flush_commit(struct gfs2_sbd *sdp)
 	log_write_header(sdp, 0, 0);
 }
 
+int bd_cmp(void *priv, struct list_head *a, struct list_head *b)
+{
+	struct gfs2_bufdata *bda, *bdb;
+
+	bda = list_entry(a, struct gfs2_bufdata, bd_le.le_list);
+	bdb = list_entry(b, struct gfs2_bufdata, bd_le.le_list);
+
+	if (bda->bd_bh->b_blocknr < bdb->bd_bh->b_blocknr)
+		return -1;
+	if (bda->bd_bh->b_blocknr > bdb->bd_bh->b_blocknr)
+		return 1;
+	return 0;
+}
+
 static void gfs2_ordered_write(struct gfs2_sbd *sdp)
 {
 	struct gfs2_bufdata *bd;
 	struct buffer_head *bh;
 	LIST_HEAD(written);
 
 	gfs2_log_lock(sdp);
+	list_sort(NULL, &sdp->sd_log_le_ordered, &bd_cmp);
 	while (!list_empty(&sdp->sd_log_le_ordered)) {
 		bd = list_entry(sdp->sd_log_le_ordered.next, struct gfs2_bufdata, bd_le.le_list);
 		list_move(&bd->bd_le.le_list, &written);