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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4C9B1C4332F for ; Thu, 20 Oct 2022 00:15:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230290AbiJTAPL (ORCPT ); Wed, 19 Oct 2022 20:15:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33856 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229675AbiJTAPH (ORCPT ); Wed, 19 Oct 2022 20:15:07 -0400 Received: from mail-wm1-x32b.google.com (mail-wm1-x32b.google.com [IPv6:2a00:1450:4864:20::32b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 84D35FAA43 for ; Wed, 19 Oct 2022 17:15:05 -0700 (PDT) Received: by mail-wm1-x32b.google.com with SMTP id c7-20020a05600c0ac700b003c6cad86f38so1180923wmr.2 for ; Wed, 19 Oct 2022 17:15:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=layalina-io.20210112.gappssmtp.com; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=pxI8kiw4rBDyzprun94lI3J+VU67DIHr00ooaxAPBxU=; b=VocGDT8YXXfmXMw5V24L7ALUOsZLW0qRtKHECWV8sWob9aM87OHJcZw+0qVD67v2r6 RMPVV3pzEkmSJOXP6OylxCeMB21btV30UelZXnHrC1BkNP6JoJ8ptPGlZ+KbhBNgviUv tAS07O5TJKQC3H83wD2m+Igd2+serrJIJHnl7UM2XwOf29mCSAnjlM/jIXFkJxME6EOs 9LgT7HxZnN5e7SPtCEmxjK4sWfu79FCTS5WfieZLsGObD54/pUclh3mkYDsL2rtBo6oy o2ci2FAwGvepobVdkBYdXWxNX35zoKTHcpKoOA6HZ48q1j2ZZiStPPJWL2LOfKBFJW7r 2zEQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=pxI8kiw4rBDyzprun94lI3J+VU67DIHr00ooaxAPBxU=; b=AiiFNHZ8zNQ2TndXnwHNdWT1jiFAZALs3zmDX+jx+dRQiXEMeCxIT7lDd1mep8Ydie iQzxLjYDeOB1ZlrXxet+Ch+quNkT1m581XzkoajRoi5TSt85kVyqSWHY2vZwsIK9Y2Rw BY9pGGIT66y4b7q4iifM6Bcx1xV8GEnRx5uh70mbKmpxGiMHQbnnLJNQJxkUG8K//LDZ GTnjRR09wzbdjy34BNA8Lc4Gc/oHlCAgTi6MIACohoeGmxeCS3UvCfF3mT2EcCtp4Ny3 taVPJ2SmM1Cg2n5ixt1WhAise1qAtyRhAzQzSZ/wTXvIeye6qHBZV/086dkiXfanN8PW VgnQ== X-Gm-Message-State: ACrzQf1eNh0I6oFXwbPKPiYObYh3ycUTitSuMmY4zOvgYh3kzvBULb18 tt1K0vabUvsde6txZggvthcgUA== X-Google-Smtp-Source: AMsMyM47optp+N0c5MrnanAte8PnrF/flGeHMCD3RaXGV80e4K6dIAfP7crRZPGDXYP8tKn3DMjtyQ== X-Received: by 2002:a05:600c:5252:b0:3c6:f478:96db with SMTP id fc18-20020a05600c525200b003c6f47896dbmr7606031wmb.116.1666224904109; Wed, 19 Oct 2022 17:15:04 -0700 (PDT) Received: from airbuntu (host86-130-134-87.range86-130.btcentralplus.com. [86.130.134.87]) by smtp.gmail.com with ESMTPSA id j18-20020a5d4492000000b0022f864164edsm15009276wrq.6.2022.10.19.17.15.03 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 19 Oct 2022 17:15:03 -0700 (PDT) Date: Thu, 20 Oct 2022 01:15:01 +0100 From: Qais Yousef To: John Stultz Cc: Alexander Gordeev , LKML , Connor O'Brien , John Dias , Rick Yiu , John Kacur , Qais Yousef , Chris Redpath , Abhijeet Dharmapurikar , Peter Zijlstra , Ingo Molnar , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Thomas Gleixner , kernel-team@android.com, "J . Avila" Subject: Re: [PATCH RFC v4 2/3] sched: Avoid placing RT threads on cores handling long softirqs Message-ID: <20221020001501.7qbqd5r4gvw3enjs@airbuntu> References: <20221003232033.3404802-1-jstultz@google.com> <20221003232033.3404802-3-jstultz@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/19/22 15:09, John Stultz wrote: > I fret there are some edge cases where on the target cpu softirqs > might be pending but ksoftirqd isn't running yet maybe due to a > lowish-prio rt task - such that the cpu could still be considered a > good target. But this seems a bit of a stretch. Could using ksoftirqd_running() instead help with robustness here? Cheers -- Qais Yousef