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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 0B45FC433B4 for ; Fri, 21 May 2021 12:47:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DCE8C613CC for ; Fri, 21 May 2021 12:47:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234415AbhEUMtE (ORCPT ); Fri, 21 May 2021 08:49:04 -0400 Received: from szxga07-in.huawei.com ([45.249.212.35]:3470 "EHLO szxga07-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234275AbhEUMtA (ORCPT ); Fri, 21 May 2021 08:49:00 -0400 Received: from dggems704-chm.china.huawei.com (unknown [172.30.72.58]) by szxga07-in.huawei.com (SkyGuard) with ESMTP id 4FmmXH4PvGzCtRC; Fri, 21 May 2021 20:44:47 +0800 (CST) Received: from lhreml724-chm.china.huawei.com (10.201.108.75) by dggems704-chm.china.huawei.com (10.3.19.181) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Fri, 21 May 2021 20:47:35 +0800 Received: from [10.47.85.3] (10.47.85.3) by lhreml724-chm.china.huawei.com (10.201.108.75) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2176.2; Fri, 21 May 2021 13:47:32 +0100 Subject: Re: Question on threaded handlers for managed interrupts To: Thomas Gleixner CC: "linux-kernel@vger.kernel.org" , "Marc Zyngier" , Peter Zijlstra , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Daniel Bristot de Oliveira , "Ingo Molnar" , Ming Lei References: <874kfxw9zv.ffs@nanos.tec.linutronix.de> <871rb1w3x8.ffs@nanos.tec.linutronix.de> From: John Garry Message-ID: <42e399d7-6b50-1669-b740-cf63620c30e1@huawei.com> Date: Fri, 21 May 2021 13:46:22 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.1.2 MIME-Version: 1.0 In-Reply-To: <871rb1w3x8.ffs@nanos.tec.linutronix.de> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.47.85.3] X-ClientProxiedBy: lhreml711-chm.china.huawei.com (10.201.108.62) To lhreml724-chm.china.huawei.com (10.201.108.75) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org + Hi Thomas, On 23/04/2021 14:01, Thomas Gleixner wrote: > On Fri, Apr 23 2021 at 12:50, Thomas Gleixner wrote: >> On Thu, Apr 22 2021 at 17:10, John Garry wrote: >> OTOH, the way how you splitted the handling into hard/thread context >> provides already the base for this. >> >> The missing piece is infrastructure at the irq/scheduler core level to >> handle this transparently. >> >> I have some horrible ideas how to solve that, but I'm sure the scheduler >> wizards can come up with a reasonable and generic solution. JFYI, A performance-related fix was recently added in the block layer, and I can no longer reproduce this hang. But I have no reason to say that it no longer exists. Thanks, John