From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752610AbbJLQKW (ORCPT ); Mon, 12 Oct 2015 12:10:22 -0400 Received: from imap.thunk.org ([74.207.234.97]:44750 "EHLO imap.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751896AbbJLQKT (ORCPT ); Mon, 12 Oct 2015 12:10:19 -0400 Date: Mon, 12 Oct 2015 12:09:48 -0400 From: "Theodore Ts'o" To: Christoph Hellwig Cc: ksummit-discuss@lists.linuxfoundation.org, linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org Subject: Re: [Ksummit-discuss] [TECH TOPIC] IRQ affinity Message-ID: <20151012160948.GD20210@thunk.org> Mail-Followup-To: Theodore Ts'o , Christoph Hellwig , ksummit-discuss@lists.linuxfoundation.org, linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org References: <20150715120708.GA24534@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150715120708.GA24534@infradead.org> User-Agent: Mutt/1.5.24 (2015-08-30) X-SA-Exim-Connect-IP: X-SA-Exim-Mail-From: tytso@thunk.org X-SA-Exim-Scanned: No (on imap.thunk.org); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Christoph, Do you think this is still an issue that would be worth discsussing at the kernel summit as a technical topic? If so, would you be willing to be responsible for kicking off the discussion for this topic? Thanks, - Ted On Wed, Jul 15, 2015 at 05:07:08AM -0700, Christoph Hellwig wrote: > Many years ago we decided to move setting of IRQ to core affnities to > userspace with the irqbalance daemon. > > These days we have systems with lots of MSI-X vector, and we have > hardware and subsystem support for per-CPU I/O queues in the block > layer, the RDMA subsystem and probably the network stack (I'm not too > familar with the recent developments there). It would really help the > out of the box performance and experience if we could allow such > subsystems to bind interrupt vectors to the node that the queue is > configured on. > > I'd like to discuss if the rationale for moving the IRQ affinity setting > fully to userspace are still correct in todays world any any pitfalls > we'll have to learn from in irqbalanced and the old in-kernel affinity > code. > _______________________________________________ > Ksummit-discuss mailing list > Ksummit-discuss@lists.linuxfoundation.org > https://lists.linuxfoundation.org/mailman/listinfo/ksummit-discuss