Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757717AbYHEO3c (ORCPT ); Tue, 5 Aug 2008 10:29:32 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755474AbYHEO3X (ORCPT ); Tue, 5 Aug 2008 10:29:23 -0400 Received: from out2.smtp.messagingengine.com ([66.111.4.26]:52888 "EHLO out2.smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755367AbYHEO3W (ORCPT ); Tue, 5 Aug 2008 10:29:22 -0400 X-Sasl-enc: gxXyGkzN1GQSYAsK6/cqwHe9o3SXxmqdZYzTRd7E7wwL 1217946560 Date: Tue, 5 Aug 2008 11:29:15 -0300 From: Henrique de Moraes Holschuh To: Theodore Tso , Robert Hancock , Alan Cox , Gabor Gombas , Tejun Heo , Elias Oltmanns , Jeff Garzik , Bartlomiej Zolnierkiewicz , James Bottomley , Pavel Machek , linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 3/5] libata: Implement disk shock protection support Message-ID: <20080805142915.GD32675@khazad-dum.debian.net> References: <4897D16F.3000504@shaw.ca> <20080805131417.GC8569@mit.edu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080805131417.GC8569@mit.edu> X-GPG-Fingerprint: 1024D/1CDB0FE3 5422 5C61 F6B7 06FB 7E04 3738 EE25 DE3F 1CDB 0FE3 User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1397 Lines: 28 On Tue, 05 Aug 2008, Theodore Tso wrote: > The real right answer though is to buy one of the laptop drives (such > as the Seagate Momentus 7200.2 or 7200.3) which has the anti-shock > detection built directly into the hard drive. That way you don't have > to have a daemon that sits in the OS waking up the CPU some 20 to 30 > times a second and burning up your battery even when the laptop is > idle. Make that 50 times a second for the kernel over a slow LPC bus IO path, plus whatever userspace needs to process that data and feed it back as an UNLOAD IMMEDIATE request... Yes, doing it inside the HD itself is *MUCH* better. But only very few disks do it, so far, I only know of those Seagates. And they are available only on SATA. So, many thinkpad owners will want "software-based" HDAPS for at least five more years, maybe more (thinkpads REALLY have a long useful life, we still see a good number of T23 in heavy use...). -- "One disk to rule them all, One disk to find them. One disk to bring them all and in the darkness grind them. In the Land of Redmond where the shadows lie." -- The Silicon Valley Tarot Henrique Holschuh -- 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/