Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964942AbVI0Ngm (ORCPT ); Tue, 27 Sep 2005 09:36:42 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964944AbVI0Ngm (ORCPT ); Tue, 27 Sep 2005 09:36:42 -0400 Received: from nproxy.gmail.com ([64.233.182.199]:20787 "EHLO nproxy.gmail.com") by vger.kernel.org with ESMTP id S964942AbVI0Ngl convert rfc822-to-8bit (ORCPT ); Tue, 27 Sep 2005 09:36:41 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:reply-to:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=qBRswB7Coj2gnx7Iq0oVcNs/rbeM2gCeuiiWcuckiiK0WjuJ8/EQKBa0kwlrl6vvkkFB5ImV/viiEBnGVrt8iT1kw6UpU0cLtp7/YZPNGupnI4QPSHVg37vxZYok9yBo93dG5hvjdnGVcGRf2xlj/Ac/8MbQNk4zWqB7kuQIsCU= Message-ID: <58cb370e050927063674bb47a7@mail.gmail.com> Date: Tue, 27 Sep 2005 15:36:40 +0200 From: Bartlomiej Zolnierkiewicz Reply-To: Bartlomiej Zolnierkiewicz To: Jens Axboe Subject: Re: [patch 0/4] ide: Break ide_lock to per-hwgroup lock Cc: Ravikiran G Thirumalai , linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org, "Shai Fultheim (Shai@scalex86.org)" , Alok Kataria In-Reply-To: <20050907193422.GS4785@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT Content-Disposition: inline References: <20050906233322.GA3642@localhost.localdomain> <20050907091923.GE4785@suse.de> <20050907192747.GC3769@localhost.localdomain> <20050907193422.GS4785@suse.de> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1478 Lines: 34 On 9/7/05, Jens Axboe wrote: > On Wed, Sep 07 2005, Ravikiran G Thirumalai wrote: > > On Wed, Sep 07, 2005 at 11:19:24AM +0200, Jens Axboe wrote: > > > On Tue, Sep 06 2005, Ravikiran G Thirumalai wrote: > > > > The following patchset breaks down the global ide_lock to per-hwgroup lock. > > > > We have taken the following approach. > > > > > > Curious, what is the point of this? > > > > > > > On smp machines with multiple ide interfaces, we take per-group lock instead > > of a global lock, there by breaking the lock to per-irq hwgroups. > > I realize the theory behind breaking up locks, I'm just wondering about > this specific case. Please show actual contention data promoting this > specific case, we don't break up locks "just because". > > I'm asking because I've never heard anyone complain about IDE lock > contention and a proper patch usually comes with analysis of why it is > needed. Since ide_lock spinlock is used for all drives as queue lock and for all controllers as IDE lock I guess that with multiple controllers there is a lot contention on it... Breaking ide_lock is fine with me however seeing numbers would greatly help in getting wider acceptance for this change, Ravikiran? Bartlomiej - 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/