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=-4.1 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 26901C433DF for ; Mon, 3 Aug 2020 15:13:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E9A56207FB for ; Mon, 3 Aug 2020 15:13:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="LBURf5Ja"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="DC0RPbpC" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728090AbgHCPNV (ORCPT ); Mon, 3 Aug 2020 11:13:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39768 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725933AbgHCPNV (ORCPT ); Mon, 3 Aug 2020 11:13:21 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 49A00C06174A for ; Mon, 3 Aug 2020 08:13:21 -0700 (PDT) From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1596467599; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=zXGEztBjn4giLdEcSrD148UX+XKQGnk+zqs22R94Q+0=; b=LBURf5Ja6M9Lac4WOtiuJ6bxV3P29YalLePHR73LPtA0WqbI3DEP5PI50sGfEKLrOxsHxk SpZq/CrnkcSwoR5GhLAuMFCxRFIuwknKHC+j2k1XLlJy2dfbZCwoq4hpTrV8+rWguLLEus 6Cb0ASJC/yoHQrrJw5p3WETehitAxGJlOldFGFjwFnKPs+HbOx+h/iROd2tFeWUZ7EsBhG VDwFIAonfMaIKyOmK5k8bevRY5d83pdzgieQQSzIVG+POWhTMuUsspi4MdsrfIgpH7v4pV Ql0+pNsiIgi39OmQmKNAHz48/jKQCCg1HESutm3gcqlHSCNFCdw3ltBQ0/JLoQ== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1596467599; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=zXGEztBjn4giLdEcSrD148UX+XKQGnk+zqs22R94Q+0=; b=DC0RPbpCWyjFYqilNHjgTKCW8agE9XURW0gniTmMsNl7HWZ5w0tXO+jy2OVEX4siXKFtfx HVmiyqaI1kWcTFCQ== To: Vladimir Oltean Cc: Kurt Kanzenbach , Alison Wang , catalin.marinas@arm.com, will@kernel.org, paulmck@kernel.org, mw@semihalf.com, leoyang.li@nxp.com, vladimir.oltean@nxp.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Anna-Maria Gleixner , Peter Zijlstra Subject: Re: [RFC PATCH] arm64: defconfig: Disable fine-grained task level IRQ time accounting In-Reply-To: <20200803114112.mrcuupz4ir5uqlp6@skbuf> References: <20200729033934.22349-1-alison.wang@nxp.com> <877dumbtoi.fsf@kurt> <20200729094943.lsmhsqlnl7rlnl6f@skbuf> <87mu3ho48v.fsf@kurt> <20200730082228.r24zgdeiofvwxijm@skbuf> <873654m9zi.fsf@kurt> <87lfiwm2bj.fsf@nanos.tec.linutronix.de> <20200803114112.mrcuupz4ir5uqlp6@skbuf> Date: Mon, 03 Aug 2020 17:13:18 +0200 Message-ID: <87d047n4oh.fsf@nanos.tec.linutronix.de> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Vladimir Oltean writes: >> 1) When irq accounting is disabled, RT throttling kicks in as >> expected. >> >> 2) With irq accounting the RT throttler does not kick in and the RCU >> stall/lockups happen. >> >> Not much, but there is clearly interaction between irq time accounting >> and scheduler accounting. >> >> Can you please reduce /proc/sys/kernel/sched_rt_runtime_us in steps of >> 50000? At least in theory, reduction should bring the throttling back. > > We already know from my original report that reducing > sched_rt_runtime_us to 80% (800000) gives us a stable system. > https://lkml.org/lkml/2020/6/4/1062 Oh. Somehow missed that. Btw, can you please use links in the form of: https://lore.kernel.org/r/$MSGID lkml.org is spotty and having the message id allows to search in the mail client as well. > What is this telling us? It seems that the fine grained irq time accounting affects the runtime accounting in some way which I haven't figured out yet. Thanks, tglx