[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, 5 insertions, 5 deletions

diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index eabdb5cce357..8eeaa53a68c9 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -78,7 +78,7 @@ struct hd_struct {
         sector_t start_sect;
         sector_t nr_sects;
         struct kobject kobj;
-        unsigned reads, read_sectors, writes, write_sectors;
+        unsigned ios[2], sectors[2];
         int policy, partno;
 };
 
@@ -89,10 +89,10 @@ struct hd_struct {
 #define GENHD_FL_SUPPRESS_PARTITION_INFO        32
 
 struct disk_stats {
-        unsigned read_sectors, write_sectors;
-        unsigned reads, writes;
-        unsigned read_merges, write_merges;
-        unsigned read_ticks, write_ticks;
+        unsigned sectors[2];
+        unsigned ios[2];
+        unsigned merges[2];
+        unsigned ticks[2];
         unsigned io_ticks;
         unsigned time_in_queue;
 };