Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935174Ab2JYJKH (ORCPT ); Thu, 25 Oct 2012 05:10:07 -0400 Received: from mail-ee0-f46.google.com ([74.125.83.46]:43960 "EHLO mail-ee0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934847Ab2JYJKD (ORCPT ); Thu, 25 Oct 2012 05:10:03 -0400 Date: Thu, 25 Oct 2012 11:09:57 +0200 From: Ingo Molnar To: Alexander Gordeev Cc: linux-kernel@vger.kernel.org, Ingo Molnar , Thomas Gleixner , Bjorn Helgaas , Suresh Siddha , Yinghai Lu , Jeff Garzik , Matthew Wilcox , x86@kernel.org, linux-pci@vger.kernel.org, linux-ide@vger.kernel.org Subject: Re: [PATCH v4 -tip 3/3] AHCI: Support multiple MSIs Message-ID: <20121025090957.GA7424@gmail.com> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1384 Lines: 32 * 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 | 93 +++++++++++++++++++++++++++++++++++++-- > drivers/ata/ahci.h | 6 +++ > drivers/ata/libahci.c | 118 ++++++++++++++++++++++++++++++++++++++++++++++--- > 3 files changed, 207 insertions(+), 10 deletions(-) Has Jeff acked this patch? Thanks, Ingo -- 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/