Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754133Ab2JBDEh (ORCPT ); Mon, 1 Oct 2012 23:04:37 -0400 Received: from mail-qa0-f46.google.com ([209.85.216.46]:59325 "EHLO mail-qa0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753398Ab2JBDEI (ORCPT ); Mon, 1 Oct 2012 23:04:08 -0400 Message-ID: <506A59A4.7060907@pobox.com> Date: Mon, 01 Oct 2012 23:04:04 -0400 From: Jeff Garzik User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:15.0) Gecko/20120911 Thunderbird/15.0.1 MIME-Version: 1.0 To: Alexander Gordeev CC: linux-kernel@vger.kernel.org, Ingo Molnar , Thomas Gleixner , Bjorn Helgaas , Suresh Siddha , Yinghai Lu , Matthew Wilcox , x86@kernel.org, linux-pci@vger.kernel.org, linux-ide@vger.kernel.org Subject: Re: [PATCH v3 -tip 5/5] AHCI: Support multiple MSIs References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1629 Lines: 38 On 10/01/2012 04:13 AM, Alexander Gordeev wrote: > Take advantage of multiple MSIs implementation on x86 - on systems with > IRQ remapping AHCI ports not only get assigned separate MSI vectors - > but also separate IRQs. As result, interrupts generated by different > ports could be serviced on different CPUs rather than on a single one. > > In cases when number of allocated MSIs is less than requested the Sharing > Last MSI mode does not get used, no matter implemented in hardware or not. > Instead, the driver assumes the advantage of multiple MSIs is negated and > falls back to the single MSI mode as if MRSM bit was set (some Intel chips > implement this strategy anyway - MRSM bit gets set even if the number of > allocated MSIs exceeds the number of implemented ports). > > Signed-off-by: Alexander Gordeev > --- > drivers/ata/ahci.c | 91 ++++++++++++++++++++++++++++++++++++-- > drivers/ata/ahci.h | 6 +++ > drivers/ata/libahci.c | 118 ++++++++++++++++++++++++++++++++++++++++++++++--- > 3 files changed, 205 insertions(+), 10 deletions(-) Acked-by: Jeff Garzik Normally, this amount of changes would -really- need to go through the libata tree. However, given the amount of dependencies, it either needs a merge tree or to go through the PCI tree...? Any maintainer comments on disposition? Jeff -- 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/