From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756255Ab0IHWGM (ORCPT ); Wed, 8 Sep 2010 18:06:12 -0400 Received: from void.printf.net ([89.145.121.20]:50388 "EHLO void.printf.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756113Ab0IHWGG (ORCPT ); Wed, 8 Sep 2010 18:06:06 -0400 Date: Wed, 8 Sep 2010 23:05:48 +0100 From: Chris Ball To: Anton Vorontsov Cc: Andrew Morton , Wolfram Sang , Albert Herranz , Matt Fleming , Ben Dooks , Pierre Ossman , linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org, linuxppc-dev@ozlabs.org Subject: Re: [PATCH 0/8] sdhci: Move real work out of an atomic context Message-ID: <20100908220548.GA7967@void.printf.net> References: <20100714130728.GA27339@oksana.dev.rtsoft.ru> <20100907153813.936db0c6.akpm@linux-foundation.org> <20100908213740.GA7550@void.printf.net> <20100908215750.GA17232@oksana.dev.rtsoft.ru> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100908215750.GA17232@oksana.dev.rtsoft.ru> 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 Hi Anton, On Thu, Sep 09, 2010 at 01:57:50AM +0400, Anton Vorontsov wrote: > Thanks! > > Would be also great if you could point out which patch causes > most of the performance drop (if any)? > > Albert, if you could find time, can you also "bisect" the > patchset? I wouldn't want to buy Nintendo WII just to debug the > perf regression. ;-) FWIW, I tried to disable multiblock > read/writes and test with SD cards, and still didn't notice > any performance drops. > > Maybe it's SDIO IRQs that cause the performance drop for the > WII case, as we delay them a little bit? Or it could be the > patch that introduces threaded IRQ handler in whole causes > it. If so, I guess we'd need to move some of the processing to > the real IRQ context, keeping the handler lockless (if > possible) or introducing a very fine grained locking. I didn't know anything about a reported performance drop, and I don't think Andrew did either -- Albert's test results don't seem to have made it to this list, or anywhere else that I can see. Could you link to/repost his comments? (I'll be testing with libertas, so that will stress-test SDIO IRQs.) Thanks, -- Chris Ball One Laptop Per Child