Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751943AbZCYSac (ORCPT ); Wed, 25 Mar 2009 14:30:32 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1750738AbZCYSaU (ORCPT ); Wed, 25 Mar 2009 14:30:20 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:45089 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750718AbZCYSaT (ORCPT ); Wed, 25 Mar 2009 14:30:19 -0400 Date: Wed, 25 Mar 2009 11:21:15 -0700 (PDT) From: Linus Torvalds X-X-Sender: torvalds@localhost.localdomain To: David Rees cc: Theodore Tso , Jan Kara , Andrew Morton , Ingo Molnar , Alan Cox , Arjan van de Ven , Peter Zijlstra , Nick Piggin , Jens Axboe , Jesper Krogh , Linux Kernel Mailing List Subject: Re: Linux 2.6.29 In-Reply-To: <72dbd3150903251109x75aa5d8ke8277247c2f292f9@mail.gmail.com> Message-ID: References: <72dbd3150903232346g5af126d7sb5ad4949a7b5041f@mail.gmail.com> <20090324091545.758d00f5@lxorguk.ukuu.org.uk> <20090324093245.GA22483@elte.hu> <20090324101011.6555a0b9@lxorguk.ukuu.org.uk> <20090324103111.GA26691@elte.hu> <20090324041249.1133efb6.akpm@linux-foundation.org> <20090325123744.GK23439@duck.suse.cz> <20090325150041.GM32307@mit.edu> <72dbd3150903251109x75aa5d8ke8277247c2f292f9@mail.gmail.com> User-Agent: Alpine 2.00 (LFD 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1165 Lines: 34 On Wed, 25 Mar 2009, David Rees wrote: > > Your Intel SSD will write streaming data 2-4 times faster than your > typical disk Don't even bother with streaming data. The problem is _never_ streaming data. Even a suck-ass laptop drive can write streaming data fast enough that people don't care. The problem is invariably that writes from different sources (much of it being metadata) interact and cause seeking. > and can be an order of magnitude faster when it comes to small, random > writes. Umm. More like two orders of magnitude or more. Random writes on a disk (even a fast one) tends to be in the hundreds of kilobytes per second. Have you worked with an Intel SSD? It does tens of MB/s on pure random writes. The problem really is gone with an SSD. And please realize that the problem for me was never 30-second stalls. For me, a 3-second stall is unacceptable. It's just very annoying. Linus -- 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/