[BLOCK] Unify the seperate read/write io stat fields into arrays

Instead of having ->read_sectors and ->write_sectors, combine the two
into ->sectors[2] and similar for the other fields. This saves a branch
several places in the io path, since we don't have to care for what the
actual io direction is. On my x86-64 box, that's 200 bytes less text in
just the core (not counting the various drivers).

Signed-off-by: Jens Axboe <axboe@suse.de>

1 files changed, 14 insertions, 15 deletions

diff --git a/drivers/block/genhd.c b/drivers/block/genhd.c
index 486ce1fdeb8c..54aec4a1ae13 100644
--- a/drivers/block/genhd.c
+++ b/drivers/block/genhd.c
@@ -391,13 +391,12 @@ static ssize_t disk_stats_read(struct gendisk * disk, char *page)
                 "%8u %8u %8llu %8u "
                 "%8u %8u %8u"
                 "\n",
-                disk_stat_read(disk, reads), disk_stat_read(disk, read_merges),
-                (unsigned long long)disk_stat_read(disk, read_sectors),
-                jiffies_to_msecs(disk_stat_read(disk, read_ticks)),
-                disk_stat_read(disk, writes), 
-                disk_stat_read(disk, write_merges),
-                (unsigned long long)disk_stat_read(disk, write_sectors),
-                jiffies_to_msecs(disk_stat_read(disk, write_ticks)),
+                disk_stat_read(disk, ios[0]), disk_stat_read(disk, merges[0]),
+                (unsigned long long)disk_stat_read(disk, sectors[0]),
+                jiffies_to_msecs(disk_stat_read(disk, ticks[0])),
+                disk_stat_read(disk, ios[1]), disk_stat_read(disk, merges[1]),
+                (unsigned long long)disk_stat_read(disk, sectors[1]),
+                jiffies_to_msecs(disk_stat_read(disk, ticks[1])),
                 disk->in_flight,
                 jiffies_to_msecs(disk_stat_read(disk, io_ticks)),
                 jiffies_to_msecs(disk_stat_read(disk, time_in_queue)));
@@ -583,12 +582,12 @@ static int diskstats_show(struct seq_file *s, void *v)
         preempt_enable();
         seq_printf(s, "%4d %4d %s %u %u %llu %u %u %u %llu %u %u %u %u\n",
                 gp->major, n + gp->first_minor, disk_name(gp, n, buf),
-                disk_stat_read(gp, reads), disk_stat_read(gp, read_merges),
-                (unsigned long long)disk_stat_read(gp, read_sectors),
-                jiffies_to_msecs(disk_stat_read(gp, read_ticks)),
-                disk_stat_read(gp, writes), disk_stat_read(gp, write_merges),
-                (unsigned long long)disk_stat_read(gp, write_sectors),
-                jiffies_to_msecs(disk_stat_read(gp, write_ticks)),
+                disk_stat_read(gp, ios[0]), disk_stat_read(gp, merges[0]),
+                (unsigned long long)disk_stat_read(gp, sectors[0]),
+                jiffies_to_msecs(disk_stat_read(gp, ticks[0])),
+                disk_stat_read(gp, ios[1]), disk_stat_read(gp, merges[1]),
+                (unsigned long long)disk_stat_read(gp, sectors[1]),
+                jiffies_to_msecs(disk_stat_read(gp, ticks[1])),
                 gp->in_flight,
                 jiffies_to_msecs(disk_stat_read(gp, io_ticks)),
                 jiffies_to_msecs(disk_stat_read(gp, time_in_queue)));
@@ -601,8 +600,8 @@ static int diskstats_show(struct seq_file *s, void *v)
                         seq_printf(s, "%4d %4d %s %u %u %u %u\n",
                                 gp->major, n + gp->first_minor + 1,
                                 disk_name(gp, n + 1, buf),
-                                hd->reads, hd->read_sectors,
-                                hd->writes, hd->write_sectors);
+                                hd->ios[0], hd->sectors[0],
+                                hd->ios[1], hd->sectors[1]);
         }
  
         return 0;