Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754607Ab0DIP4M (ORCPT ); Fri, 9 Apr 2010 11:56:12 -0400 Received: from mail-vw0-f46.google.com ([209.85.212.46]:41414 "EHLO mail-vw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752870Ab0DIP4I (ORCPT ); Fri, 9 Apr 2010 11:56:08 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:subject:to:cc:in-reply-to:references; b=amB0OPh56pcwEPsLJNXPkgpH5gD4ijA4BNuD7MQrIHqwN+mzcdJIYLZ/bnjLU0dPsz l95UsK80aJpP7UVNkA2+7OtdvsgBzcZ0SAW60Wzo6ZJMu+apHWBGpNxZdbD81qdRmYD9 Aw9ZA20G3F82InpjH1LzFchaEup2HJe5692ro= Message-ID: <4bbf4e14.a215f10a.4c5c.41c9@mx.google.com> Date: Fri, 09 Apr 2010 08:56:04 -0700 (PDT) From: Ben Gamari Subject: Re: 32GB SSD on USB1.1 P3/700 == ___HELL___ (2.6.34-rc3) To: Andreas Mohr , Bill Davidsen Cc: Andreas Mohr , Jens Axboe , Wu Fengguang , linux-kernel@vger.kernel.org In-Reply-To: <20100408203526.GA15426@rhlx01.hs-esslingen.de> References: <20100404221349.GA18036@rhlx01.hs-esslingen.de> <4BBE38B9.6020507@tmr.com> <20100408203526.GA15426@rhlx01.hs-esslingen.de> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1916 Lines: 44 On Thu, 8 Apr 2010 22:35:26 +0200, Andreas Mohr wrote: > On Thu, Apr 08, 2010 at 04:12:41PM -0400, Bill Davidsen wrote: > > Andreas Mohr wrote: > >> Clearly there's a very, very important limiter somewhere in bio layer > >> missing or broken, a 300M dd /dev/zero should never manage to put > >> such an onerous penalty on a system, IMHO. > >> > > You are using a USB 1.1 connection, about the same speed as a floppy. If > > Ahahahaaa. A rather distant approximation given a speed of 20kB/s vs. 987kB/s ;) > (but I get the point you're making here) > > I'm not at all convinced that USB2.0 would fare any better here, though: > after all we are buffering the file that is written to the device > - after the fact! > (plus there are many existing complaints of people that copying of large files > manages to break entire machines, and I doubt many of those were using > USB1.1) > https://bugzilla.kernel.org/show_bug.cgi?id=13347 > https://bugzilla.kernel.org/show_bug.cgi?id=7372 > And many other reports. Indeed. I have found this to be a persistent problem and I really wish there were more interest in debugging this. I have tried bringing the community's resources to bear on this issue several[1] times, and each time we fail to get enough of the right eyes looking at it or developer interest simply vanishes. I've started putting together a list[2] of pertinent threads/patches/bugs/data in hopes that this will lower the energy barrier of getting up to speed on this issue. Hopefully this will help. Cheers, - Ben [1] https://bugzilla.kernel.org/show_bug.cgi?id=12309 [2] http://goldnerlab.physics.umass.edu/wiki/BenGamari/IoWaitLatency -- 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/