Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753103Ab1CJPcd (ORCPT ); Thu, 10 Mar 2011 10:32:33 -0500 Received: from smtprelay02.ispgateway.de ([80.67.31.29]:43245 "EHLO smtprelay02.ispgateway.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752994Ab1CJPcb (ORCPT ); Thu, 10 Mar 2011 10:32:31 -0500 Message-ID: <4D78EF5C.5090504@ladisch.de> Date: Thu, 10 Mar 2011 16:33:48 +0100 From: Clemens Ladisch User-Agent: Thunderbird 2.0.0.24 (Windows/20100228) MIME-Version: 1.0 To: Roland Dreier CC: "H. Peter Anvin" , Thomas Gleixner , Micha Nelissen , Jesse Barnes , Ingo Molnar , x86@kernel.org, "Venkatesh Pallipadi (Venki)" , linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, Matthew Wilcox Subject: Re: [PATCH] Add support for multiple MSI on x86 References: <4D583E31.4070507@neli.hopto.org> <20110304103634.4641ae36@jbarnes-desktop> <4D714357.3010807@neli.hopto.org> <35bd5f56-658b-48e3-a376-b07350a29cf6@email.android.com> In-Reply-To: Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Df-Sender: linux-kernel@cl.domainfactory-kunde.de Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 901 Lines: 24 Roland Dreier wrote: > > Yes, but there are MSI devices in the field... > > But do any of them benefit from having multiple interrupt vectors available? > > If I recall correct, willy was motivated by AHCI performance to try this out, > and in the end things didn't go any faster using multiple MSI. > > The big win with multiple interrupt vectors is when you have independent > queues that you can point different CPUs at, and give each CPU its own > interrupt. And this is how AHCI is designed, but libahci.c currently wraps its interrupt handler in a device-wide lock. I don't know if that test also reorganized the driver code. Regards, Clemens -- 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/