From mboxrd@z Thu Jan 1 00:00:00 1970 From: Amir Vadai Subject: Re: [PATCH net-next 1/9] net/mlx4_core: Enforce irq affinity changes immediatly Date: Mon, 19 May 2014 14:33:32 +0300 Message-ID: <5379EC0C.5070004@mellanox.com> References: <1399880605-28772-1-git-send-email-amirv@mellanox.com> <1399880605-28772-2-git-send-email-amirv@mellanox.com> <1400358787.2647.65.camel@deadeye.wl.decadent.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit Cc: "David S. Miller" , , Yevgeny Petrilin , Or Gerlitz , Yuval Atias To: Ben Hutchings Return-path: Received: from eu1sys200aog114.obsmtp.com ([207.126.144.137]:36549 "EHLO eu1sys200aog114.obsmtp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752269AbaESLdj (ORCPT ); Mon, 19 May 2014 07:33:39 -0400 In-Reply-To: <1400358787.2647.65.camel@deadeye.wl.decadent.org.uk> Sender: netdev-owner@vger.kernel.org List-ID: On 5/17/2014 11:33 PM, Ben Hutchings wrote: > On Mon, 2014-05-12 at 10:43 +0300, Amir Vadai wrote: >> From: Yuval Atias >> >> During heavy traffic, napi is constatntly polling the complition queue >> and no interrupt is fired. Because of that, changes to irq affinity are >> ignored until traffic is stopped and resumed. >> >> By registering to the irq notifier mechanism, and forcing interrupt when >> affinity is changed, irq affinity changes will be immediatly enforced. > [...] > > This somewhat breaks ARFS in your driver, as that depends on IRQ > affinity notification. Interesting... I missed the fact that irq_set_affinity_notifier is 'set' and not 'add'. So, do you have objection if I change the API to have a list of notifiers instead of only one? > > It is also not safe to put an IRQ affinity notification function in a > module currently, as the work item for notification doesn't carry a > module reference and could be called after the module is removed. I can get a module reference when a notifier is added and put it when the notifier is removed. Thanks, Amir > > Ben. >