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 E6421C433B4 for ; Wed, 14 Apr 2021 13:13:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BDD22600CD for ; Wed, 14 Apr 2021 13:13:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1351148AbhDNNNm (ORCPT ); Wed, 14 Apr 2021 09:13:42 -0400 Received: from smtpout1.mo529.mail-out.ovh.net ([178.32.125.2]:36773 "EHLO smtpout1.mo529.mail-out.ovh.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S244296AbhDNNNk (ORCPT ); Wed, 14 Apr 2021 09:13:40 -0400 Received: from mxplan5.mail.ovh.net (unknown [10.109.146.192]) by mo529.mail-out.ovh.net (Postfix) with ESMTPS id 8FE409A41E62; Wed, 14 Apr 2021 15:13:17 +0200 (CEST) Received: from kaod.org (37.59.142.106) by DAG4EX1.mxp5.local (172.16.2.31) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2242.4; Wed, 14 Apr 2021 15:13:17 +0200 Authentication-Results: garm.ovh; auth=pass (GARM-106R00692793ddd-07f1-4232-92a8-daead18c2131, 38A808AD2D0D3C4A59D9F430F89D181E503BD305) smtp.auth=clg@kaod.org X-OVh-ClientIp: 90.89.73.13 Subject: Re: [PATCH] genirq: reduce irqdebug bouncing cachelines To: Thomas Gleixner , Nicholas Piggin CC: References: <20210402132037.574661-1-npiggin@gmail.com> <87im4u2vxx.ffs@nanos.tec.linutronix.de> <2dae4501-6f01-1b32-4b69-1dfc94c93425@kaod.org> <87wnt71xmm.ffs@nanos.tec.linutronix.de> <87tuoax79f.ffs@nanos.tec.linutronix.de> From: =?UTF-8?Q?C=c3=a9dric_Le_Goater?= Message-ID: <8f7b2768-fe69-b1eb-8fc0-dc77a394ae99@kaod.org> Date: Wed, 14 Apr 2021 15:13:14 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.1 MIME-Version: 1.0 In-Reply-To: <87tuoax79f.ffs@nanos.tec.linutronix.de> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 8bit X-Originating-IP: [37.59.142.106] X-ClientProxiedBy: DAG3EX1.mxp5.local (172.16.2.21) To DAG4EX1.mxp5.local (172.16.2.31) X-Ovh-Tracer-GUID: 754c5738-ed00-444e-9a70-b76b5110eec9 X-Ovh-Tracer-Id: 16892157780021054429 X-VR-SPAMSTATE: OK X-VR-SPAMSCORE: -100 X-VR-SPAMCAUSE: gggruggvucftvghtrhhoucdtuddrgeduledrudeluddgiedvucetufdoteggodetrfdotffvucfrrhhofhhilhgvmecuqfggjfdpvefjgfevmfevgfenuceurghilhhouhhtmecuhedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmnecujfgurhepuffvfhfhkffffgggjggtgfhisehtkeertddtfeejnecuhfhrohhmpeevrogurhhitggpnfgvpgfiohgrthgvrhcuoegtlhhgsehkrghougdrohhrgheqnecuggftrfgrthhtvghrnhepjeekudeuudevleegudeugeekleffveeludejteffiedvledvgfekueefudehheefnecukfhppedtrddtrddtrddtpdefjedrheelrddugedvrddutdeinecuvehluhhsthgvrhfuihiivgeptdenucfrrghrrghmpehmohguvgepshhmthhpqdhouhhtpdhhvghlohepmhigphhlrghnhedrmhgrihhlrdhovhhhrdhnvghtpdhinhgvtheptddrtddrtddrtddpmhgrihhlfhhrohhmpegtlhhgsehkrghougdrohhrghdprhgtphhtthhopehtghhlgieslhhinhhuthhrohhnihigrdguvg Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 4/13/21 10:24 PM, Thomas Gleixner wrote: > On Tue, Apr 13 2021 at 14:16, Cédric Le Goater wrote: >>>> We could test irq_settings_no_debug() directly under handle_nested_irq() >>>> and handle_irq_event_percpu() to avoid calling note_interrupt(), just >>>> like we do for noirqdebug. >>> >>> We can do that, but then we should not just make it: >>> >>> if (!irqnodebug && !irq_settings_no_debug(desc)) >>> note_interrupt(...); >>> >>> Instead have only one condition: >>> >>> if (!irq_settings_no_debug(desc)) >>> note_interrupt(...); >>> >>> See the uncompiled delta patch below. >> >> I merged this second part with the first and gave IRQF_NO_DEBUG a try >> on P8 and P9 systems and all looked fine. I should send both patches >> after IRQF_NO_AUTOEN is merged in mainline. > > Does having that NODEBUG flag set on the IPI irqs make a measurable > difference or is it just too small to matter? It does not add much benefits on the 2s and 4s systems but I will give it a try on bigger ones when I can grab them. Then we can decide if it is worth merging. Thanks, C.