From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A3B2BC4360F for ; Mon, 18 Feb 2019 07:26:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 720C0218C3 for ; Mon, 18 Feb 2019 07:26:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728794AbfBRH0H (ORCPT ); Mon, 18 Feb 2019 02:26:07 -0500 Received: from Galois.linutronix.de ([146.0.238.70]:55843 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727423AbfBRH0G (ORCPT ); Mon, 18 Feb 2019 02:26:06 -0500 Received: from p5492e0d8.dip0.t-ipconnect.de ([84.146.224.216] helo=nanos) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1gvdJG-00069U-27; Mon, 18 Feb 2019 08:25:50 +0100 Date: Mon, 18 Feb 2019 08:25:49 +0100 (CET) From: Thomas Gleixner To: Ming Lei cc: LKML , Christoph Hellwig , Bjorn Helgaas , Jens Axboe , linux-block@vger.kernel.org, Sagi Grimberg , linux-nvme@lists.infradead.org, linux-pci@vger.kernel.org, Keith Busch , Marc Zyngier , Sumit Saxena , Kashyap Desai , Shivasharan Srikanteshwara Subject: Re: [patch v6 7/7] genirq/affinity: Add support for non-managed affinity sets In-Reply-To: <20190218024922.GA27779@ming.t460p> Message-ID: References: <20190216171306.403545970@linutronix.de> <20190216172228.869750763@linutronix.de> <20190217134522.GH7296@ming.t460p> <20190218024922.GA27779@ming.t460p> User-Agent: Alpine 2.21 (DEB 202 2017-01-01) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Ming, On Mon, 18 Feb 2019, Ming Lei wrote: > On Sun, Feb 17, 2019 at 08:17:05PM +0100, Thomas Gleixner wrote: > > I don't see how that would break blk-mq. The unmanaged set is not used by > > the blk-mq stuff, that's some driver internal voodoo. So blk-mq still gets > > a perfectly spread and managed interrupt set for the queues. > > >From the discussion above, the use case is for megaraid_sas. And one of the > two interrupt sets(managed and non-managed) will be chosen according to > workloads runtime. > > Each interrupt set actually defines one blk-mq queue mapping, and the > queue mapping needs to respect the rule I mentioned now. However, > non-managed affinity can be changed to any way anytime by user-space. > > Recently HPSA tried to add one module parameter to use non-managed > IRQ[1]. > > Also NVMe RDMA uses non-managed interrupts, and at least one CPU hotplug > issue is never fixed yet[2]. > > [1] https://marc.info/?t=154387665200001&r=1&w=2 > [2] https://www.spinics.net/lists/linux-block/msg24140.html Interesting. I misread the description which megasas folks provided then. I'll drop that patch and get the other lot merged. Thanks for your work and help with that! Thanks, tglx