Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758078AbYHZMsZ (ORCPT ); Tue, 26 Aug 2008 08:48:25 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754124AbYHZMsQ (ORCPT ); Tue, 26 Aug 2008 08:48:16 -0400 Received: from serv2.oss.ntt.co.jp ([222.151.198.100]:53968 "EHLO serv2.oss.ntt.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753915AbYHZMsQ (ORCPT ); Tue, 26 Aug 2008 08:48:16 -0400 Subject: [PATCH] virtio_blk: use noop elevator by default From: Fernando Luis =?ISO-8859-1?Q?V=E1zquez?= Cao To: rusty@rustcorp.com.au Cc: linux-kernel@vger.kernel.org Content-Type: text/plain Organization: NTT Open Source Software Center Date: Tue, 26 Aug 2008 21:48:14 +0900 Message-Id: <1219754894.7235.44.camel@sebastian.kern.oss.ntt.co.jp> Mime-Version: 1.0 X-Mailer: Evolution 2.22.3.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1426 Lines: 42 Hi Rusty, Would it make sense to use noop by default? After all we do not know what is behind the backend driver and the hypervisor is likely to do its own scheduling anyway. I guess this is the reason the Xen guys took this approach. What do you think about the patch below? - Fernando --- From: Fernando Luis Vazquez Cao Subject: [PATCH] virtio_blk: use noop elevator by default Using the noop elevator by default seems to be safest bet because we do not know what is behind the backend driver and the hypervisor is likely to do its own scheduling anyway. Signed-off-by: Fernando Luis Vazquez Cao --- diff -urNp linux-2.6.27-rc4/drivers/block/virtio_blk.c linux-2.6.27-rc4-fixes/drivers/block/virtio_blk.c --- linux-2.6.27-rc4/drivers/block/virtio_blk.c 2008-08-26 21:26:01.000000000 +0900 +++ linux-2.6.27-rc4-fixes/drivers/block/virtio_blk.c 2008-08-26 21:22:03.000000000 +0900 @@ -237,6 +237,8 @@ static int virtblk_probe(struct virtio_d goto out_put_disk; } + elevator_init(rq, "noop"); + if (index < 26) { sprintf(vblk->disk->disk_name, "vd%c", 'a' + index % 26); } else if (index < (26 + 1) * 26) { -- 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/