Commit 4a36d08d authored by Bob Peterson's avatar Bob Peterson Committed by Steven Whitehouse
Browse files

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: default avatarBob Peterson <rpeterso@redhat.com>
Signed-off-by: default avatarSteven Whitehouse <swhiteho@redhat.com>
parent 66fc061b

fs/gfs2/log.c

+16 −0
Original line number Diff line number Diff line
@@ -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"
@@ -566,6 +567,20 @@ 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;
@@ -573,6 +588,7 @@ static void gfs2_ordered_write(struct gfs2_sbd *sdp) 
	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);