Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751410AbVKDHQ2 (ORCPT ); Fri, 4 Nov 2005 02:16:28 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751416AbVKDHQ2 (ORCPT ); Fri, 4 Nov 2005 02:16:28 -0500 Received: from ns.virtualhost.dk ([195.184.98.160]:62982 "EHLO virtualhost.dk") by vger.kernel.org with ESMTP id S1751410AbVKDHQ2 (ORCPT ); Fri, 4 Nov 2005 02:16:28 -0500 Date: Fri, 4 Nov 2005 08:17:26 +0100 From: Jens Axboe To: Jeff Garzik Cc: Linux Kernel Mailing List Subject: Re: [BLOCK] Unify the seperate read/write io stat fields into arrays Message-ID: <20051104071725.GV26049@suse.de> References: <200511021704.jA2H4X4u027306@hera.kernel.org> <436AD3F6.2050501@pobox.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <436AD3F6.2050501@pobox.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4293 Lines: 92 On Thu, Nov 03 2005, Jeff Garzik wrote: > Linux Kernel Mailing List wrote: > >tree fe4ce823e638ded151edcb142f28a240860f0d33 > >parent d72d904a5367ad4ca3f2c9a2ce8c3a68f0b28bf0 > >author Jens Axboe Tue, 01 Nov 2005 09:26:16 +0100 > >committer Jens Axboe 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 > > > > 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 majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/