Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933297AbcLGWrR (ORCPT ); Wed, 7 Dec 2016 17:47:17 -0500 Received: from mail-vk0-f66.google.com ([209.85.213.66]:33692 "EHLO mail-vk0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932583AbcLGWrQ (ORCPT ); Wed, 7 Dec 2016 17:47:16 -0500 MIME-Version: 1.0 In-Reply-To: <20161207224941.GA25959@localhost.localdomain> References: <20161207220348.8572-1-ddstreet@ieee.org> <20161207224414.GE22478@localhost.localdomain> <20161207224941.GA25959@localhost.localdomain> From: Dan Streetman Date: Wed, 7 Dec 2016 17:46:34 -0500 X-Google-Sender-Auth: qVUiOvsHGm5adB7ghjJyps2UJYQ Message-ID: Subject: Re: [PATCH] nvme: use the correct msix vector for each queue To: Keith Busch Cc: Jens Axboe , linux-nvme@lists.infradead.org, linux-kernel , Dan Streetman Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1004 Lines: 21 On Wed, Dec 7, 2016 at 5:49 PM, Keith Busch wrote: > On Wed, Dec 07, 2016 at 05:36:00PM -0500, Dan Streetman wrote: >> On Wed, Dec 7, 2016 at 5:44 PM, Keith Busch wrote: >> > pci_alloc_irq_vectors doesn't know you intend to make the first >> > vector special, so it's going to come up with a CPU affinity from >> > blk_mq_pci_map_queues that clashes with what you've programmed in the >> > IO completion queues. >> >> I don't follow. You're saying you mean to share cq_vector 0 between >> the admin queue and io queue 1? > > I'm just saying that blk-mq's hctx mapping will end up choosing a queue > who's vector is mapped to a different CPU, and we don't want that. > > We are currently sharing the first IO queue's interrupt vector with > the admin queue's on purpose. Are you saying there's something wrong > with that? that's intentional? Ok then. That's extremely non-obvious. Is there a reason you want to share the interrupt between the queues?