From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com ([209.132.183.28]:48878 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750716AbeAPBe6 (ORCPT ); Mon, 15 Jan 2018 20:34:58 -0500 Date: Tue, 16 Jan 2018 09:34:40 +0800 From: Ming Lei To: Thomas Gleixner Cc: Jens Axboe , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, Christoph Hellwig , Laurence Oberman , Mike Snitzer Subject: Re: [PATCH 0/2] genirq/affinity: try to make sure online CPU is assgined to irq vector Message-ID: <20180116013439.GB3213@ming.t460p> References: <20180115160345.2611-1-ming.lei@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: Sender: linux-block-owner@vger.kernel.org List-Id: linux-block@vger.kernel.org On Mon, Jan 15, 2018 at 06:43:47PM +0100, Thomas Gleixner wrote: > On Tue, 16 Jan 2018, Ming Lei wrote: > > These two patches fixes IO hang issue reported by Laurence. > > > > 84676c1f21 ("genirq/affinity: assign vectors to all possible CPUs") > > may cause one irq vector assigned to all offline CPUs, then this vector > > can't handle irq any more. > > > > The 1st patch moves irq vectors spread into one function, and prepares > > for the fix done in 2nd patch. > > > > The 2nd patch fixes the issue by trying to make sure online CPUs assigned > > to irq vector. > > Which means it's completely undoing the intent and mechanism of managed > interrupts. Not going to happen. As I replied in previous mail, some of offline CPUs may be assigned to some of irq vectors after we assign vectors to all possible CPUs, some of which are not present. > > Which driver is that which abuses managed interrupts and does not keep its > queues properly sorted on cpu hotplug? It isn't related with driver/device, and I can trigger this issue on NVMe easily except for HPSA. Thanks, Ming