Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Mon, 7 Jan 2002 20:34:19 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Mon, 7 Jan 2002 20:34:01 -0500 Received: from air-1.osdl.org ([65.201.151.5]:56330 "EHLO osdlab.pdx.osdl.net") by vger.kernel.org with ESMTP id ; Mon, 7 Jan 2002 20:33:53 -0500 Date: Mon, 7 Jan 2002 17:44:35 -0800 (PST) From: "Randy.Dunlap" X-X-Sender: To: Jens Axboe cc: Subject: Re: bounce buffer usage In-Reply-To: <20011223150940.E7438@suse.de> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sun, 23 Dec 2001, Jens Axboe wrote: | On Fri, Dec 21 2001, Randy.Dunlap wrote: | > Are there any drivers in 2.4.x that support highmem directly, | > or is all of that being done in 2.5.x (BIO patches)? | | 2.4 + my block-highmem patches support direct highmem I/O. | | > Would it be useful to try this with a 2.5.1 kernel? | | Sure OK, here's 'fillmem 700' run against 5 kernels as described below, with my bounce io/swap statistics patch added. All tests are 6 instances of "fillmem 700" (700 MB) on a 4-way 4 GB x86 VA 4450 server. I'm including a reduced version of /proc/stat -- before and after the fillmem test in each case. Let me know if you'd like to see other variations. =====bounce-stats-2416.txt Linux 2.4.16 with bounce io/swap stats added: elapsed run time: 2 min:58 sec. BEFORE fillmem: page 12847 816 swap 3 0 ctxt 11542 bounce io 23966 476 bounce swap io 0 0 AFTER fillmem: page 686457 725766 swap 168354 181146 ctxt 4110183 bounce io 1311468 195826 bounce swap io 160892 24385 =====bounce-stats-low-2416.txt Linux 2.4.16 with bounce io/swap stats added and some swap forced to low memory: elapsed run time: 3 min:11 sec. BEFORE fillmem: page 12899 815 swap 3 0 ctxt 12951 bounce io 24046 476 bounce swap io 0 0 AFTER fillmem: page 685718 854715 swap 168157 213360 ctxt 675273 bounce io 24410 164072 bounce swap io 0 20415 =====bounce-stats-2416-highio.txt Linux 2.4.16 plus Jens's 2.4.x block-highmem patches, with CONFIG_HIGHIO=y: elapsed run time: 2 min:45 sec. BEFORE fillmem: page 103940 1198 swap 3 0 ctxt 24409 bounce io 23978 576 bounce swap io 0 0 AFTER fillmem: page 735853 651670 swap 157926 162541 ctxt 2328418 bounce io 1284928 186422 bounce swap io 157568 23194 =====bounce-stats-2416-nohighio.txt Linux 2.4.16 plus Jens's 2.4.x block-highmem patches, with CONFIG_HIGHIO=n: elapsed run time: 3 min:00 sec. BEFORE fillmem: page 13955 3177 swap 3 0 ctxt 20528 bounce io 26068 4052 bounce swap io 0 0 AFTER fillmem: page 707172 741396 swap 173251 184456 ctxt 1013516 bounce io 1346488 156778 bounce swap io 165001 19066 =====bounce-stats-252-pre6.txt Linux 2.5.2-pre6 with bounce io/swap stats added: elapsed run time: 2 min:00 sec. BEFORE fillmem: page 16569 3318 swap 3 0 ctxt 46747 bounce io 30830 2080 bounce swap io 0 0 AFTER fillmem: page 479343 546956 swap 115688 136051 ctxt 111294 bounce io 955046 427172 bounce swap io 115519 53094 -- ~Randy - 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/