On Thu, Nov 03 2005, Jeff Garzik wrote:
> Linux Kernel Mailing List wrote:
> >tree fe4ce823e638ded151edcb142f28a240860f0d33
> >parent d72d904a5367ad4ca3f2c9a2ce8c3a68f0b28bf0
> >author Jens Axboe <[email protected]> Tue, 01 Nov 2005 09:26:16 +0100
> >committer Jens Axboe <[email protected]> Tue, 01 Nov 2005 09:26:16 +0100
> >
> >[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 <[email protected]>
> >
> > drivers/block/genhd.c | 29 ++++++++++++++---------------
> > drivers/block/ll_rw_blk.c | 40 ++++++++++++----------------------------
> > drivers/md/linear.c | 10 +++-------
> > drivers/md/md.c | 4 ++--
> > drivers/md/multipath.c | 10 +++-------
> > drivers/md/raid0.c | 10 +++-------
> > drivers/md/raid1.c | 12 ++++--------
> > drivers/md/raid10.c | 12 ++++--------
> > drivers/md/raid5.c | 10 +++-------
> > drivers/md/raid6main.c | 12 ++++--------
> > fs/partitions/check.c | 7 ++++---
> > include/linux/genhd.h | 10 +++++-----
> > 12 files changed, 61 insertions(+), 105 deletions(-)
> >
> >diff --git a/drivers/block/genhd.c b/drivers/block/genhd.c
> >index 486ce1f..54aec4a 100644
> >--- a/drivers/block/genhd.c
> >+++ b/drivers/block/genhd.c
> >@@ -391,13 +391,12 @@ static ssize_t disk_stats_read(struct ge
> > "%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_fil
> > 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)));
>
> While the overall patch is OK, the use of magic numbers makes the code
> less readable. fsck if I know whether "[0]" represents read or write.
Does it matter, you know that they are reads and writes obviously. But
yes, using READ/WRITE would be nicer. I'll queue it up.
--
Jens Axboe
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
