From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753513AbcKHPLy (ORCPT ); Tue, 8 Nov 2016 10:11:54 -0500 Received: from verein.lst.de ([213.95.11.211]:42049 "EHLO newverein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752626AbcKHPLw (ORCPT ); Tue, 8 Nov 2016 10:11:52 -0500 Date: Tue, 8 Nov 2016 16:11:50 +0100 From: Christoph Hellwig To: Hannes Reinecke Cc: Christoph Hellwig , Thomas Gleixner , Jens Axboe , linux-block@vger.kernel.org, linux-pci@vger.kernel.org, Linux Kernel Mailinglist , Hannes Reinecke Subject: Re: [RFC PATCH] pci: add pci_irq_get_affinity_vector() Message-ID: <20161108151150.GA14002@lst.de> References: <1478591241-123356-1-git-send-email-hare@suse.de> <20161108145652.GA12817@lst.de> <40d6e3d4-7e63-0d23-3e5c-a877cebd539a@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <40d6e3d4-7e63-0d23-3e5c-a877cebd539a@suse.de> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Nov 08, 2016 at 04:08:51PM +0100, Hannes Reinecke wrote: > The use-case here is that one needs to feed the MSI-X index into the driver > command structure. While we can extract that number trivially with scsi-mq, > but for scsi-sq we don't have such means. > The main impetus of this RFC is to figure out if such a function would have > a chance of getting upstream, or if I have to continue use cpumaps in the > drivers. There should be no need for a cpumap, nor should there be any need for a lookup. Driver will need the vector index for some admin ops, but it can store it in it's driver-private queue structure (e.g. take a look at the cq_vector field in NVMe). Drivers really should not need this during I/O, but if for some weird reason they do that driver specific field is trivially reachable through the hw_ctx which gets passed to ->queue_rq.