[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>
diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index eabdb5c..8eeaa53 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -78,7 +78,7 @@
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 @@
#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;
};