From owner-freebsd-current Mon Nov 13 23:26:02 1995 Return-Path: owner-current Received: (from root@localhost) by freefall.freebsd.org (8.6.12/8.6.6) id XAA04369 for current-outgoing; Mon, 13 Nov 1995 23:26:02 -0800 Received: from Root.COM (implode.Root.COM [198.145.90.17]) by freefall.freebsd.org (8.6.12/8.6.6) with ESMTP id XAA04364 for ; Mon, 13 Nov 1995 23:25:59 -0800 Received: from corbin.Root.COM (corbin [198.145.90.50]) by Root.COM (8.6.12/8.6.5) with ESMTP id XAA27929; Mon, 13 Nov 1995 23:25:57 -0800 Received: from localhost (localhost [127.0.0.1]) by corbin.Root.COM (8.6.12/8.6.5) with SMTP id XAA00188; Mon, 13 Nov 1995 23:25:53 -0800 Message-Id: <199511140725.XAA00188@corbin.Root.COM> To: uhclem%nemesis@fw.ast.com (Frank Durda IV) cc: simonm@dcs.gla.ac.uk, davidg@root.com, current@freebsd.org Subject: Re: Disk I/O that binds In-reply-to: Your message of "Mon, 13 Nov 95 22:34:00 +0700." From: David Greenman Reply-To: davidg@root.com Date: Mon, 13 Nov 1995 23:25:53 -0800 Sender: owner-current@freebsd.org Precedence: bulk Attached is the patch to disable disk block sorting. It's interesting - I've been doing some tests here with disksort disabled and I'm actually seeing a performance increase. I'm sure the algorithm is doing what it was written to do...but... My (SCSI) drive supports tagged queueing, but even with that disabled things seem to be a bit faster. Hmmm. -DG Index: ufs_disksubr.c =================================================================== RCS file: /home/ncvs/src/sys/ufs/ufs/ufs_disksubr.c,v retrieving revision 1.19 diff -c -r1.19 ufs_disksubr.c *** 1.19 1995/09/16 17:04:06 --- ufs_disksubr.c 1995/11/14 06:30:43 *************** *** 81,86 **** --- 81,87 ---- return; } + #if 0 /* * If we lie after the first (currently active) request, then we * must locate the second request list and add ourselves to it. *************** *** 135,140 **** --- 136,146 ---- * Neither a second list nor a larger request... we go at the end of * the first list, which is the same as the end of the whole schebang. */ + #endif + + bq = ap->b_actf; + while (bq->b_actf) + bq = bq->b_actf; insert: bp->b_actf = bq->b_actf; bq->b_actf = bp;