GFS2: Sort buffer lists by inplace block number
This patch simply sort the data and metadata buffer lists by their
inplace block number. This makes gfs2_log_flush issue the inplace IO
in sequential order, which will hopefully speed up writing the IO
out to disk.
Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
diff --git a/fs/gfs2/lops.c b/fs/gfs2/lops.c
index 6c33d7b..cb017a6 100644
--- a/fs/gfs2/lops.c
+++ b/fs/gfs2/lops.c
@@ -16,6 +16,7 @@
#include <linux/gfs2_ondisk.h>
#include <linux/bio.h>
#include <linux/fs.h>
+#include <linux/list_sort.h>
#include "gfs2.h"
#include "incore.h"
@@ -401,6 +402,20 @@
kunmap_atomic(kaddr);
}
+static int blocknr_cmp(void *priv, struct list_head *a, struct list_head *b)
+{
+ struct gfs2_bufdata *bda, *bdb;
+
+ bda = list_entry(a, struct gfs2_bufdata, bd_list);
+ bdb = list_entry(b, struct gfs2_bufdata, bd_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_before_commit(struct gfs2_sbd *sdp, unsigned int limit,
unsigned int total, struct list_head *blist,
bool is_databuf)
@@ -413,6 +428,7 @@
__be64 *ptr;
gfs2_log_lock(sdp);
+ list_sort(NULL, blist, blocknr_cmp);
bd1 = bd2 = list_prepare_entry(bd1, blist, bd_list);
while(total) {
num = total;