From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f172.google.com (mail-pl1-f172.google.com [209.85.214.172]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D81361DFDBE for ; Mon, 6 Jan 2025 20:39:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736195966; cv=none; b=NFZ3UKjP814t7Yv9gxOLunoID0IDy4mfOte7ZOqQNyBS9KPlk9xgIvqBfiHylbptvfwl7bM6NU2so8AsHSqjFQ0MfTvUKCVJPl/wVLlCaoT/P90ZYALpefpS77QeLzoDo+Uu7aUhZlCHxZwRH1PtGeoV+89wz6TpOCWCiEaWTKo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736195966; c=relaxed/simple; bh=pcrojBMTqDOLGIXh9cpNY1AYQU3MEu1oaESevo7lM34=; h=Date:From:To:cc:Subject:In-Reply-To:Message-ID:References: MIME-Version:Content-Type; b=NTIXMHiez03pLn/2GP7YdMDyQfXLb7M3GmRNvL4W8xDX9WPB13E6MIXs7rf+kvMg2J0w7ZvFLlJG5xizqjBhPpzMIX1qKma1RV1CBHYjmZqNCObslI2aoq0GWyoGXU7wgsE6AlNkLUARx87X+6kTe6jLArnX+N0OPRbrMOjd65Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=sGtJG8zI; arc=none smtp.client-ip=209.85.214.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="sGtJG8zI" Received: by mail-pl1-f172.google.com with SMTP id d9443c01a7336-2163affd184so1075ad.1 for ; Mon, 06 Jan 2025 12:39:24 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1736195964; x=1736800764; darn=vger.kernel.org; h=mime-version:references:message-id:in-reply-to:subject:cc:to:from :date:from:to:cc:subject:date:message-id:reply-to; bh=qO2YViZm8il4nDX9JseJbZRFAqeiALGsHheIiNc3LqE=; b=sGtJG8zI1Ck/cNPtre5LAyBKpL6RG606NMojd+4S5bYIVcK5h6L5nlyGlL112q27l4 Pl4yixU6oOfbDp9QkapXeO37ZNtcVrxJLPJZtXXrA/MijT/EKwAfXWhEVurRWiSrRtYv S7FLjpq8bwU7y2mJ/2RPK3FKqawHpBCWGpq3cJHaGnTfw1+55zpFEvmkGSlScG3ab6ZN GB4b+YUyfWw8fRlbcsImS0hnmPhPzZEahUSRZ1CxjAo4iYohyxu7VVm8lm1afQ4rAMdN OXUfp4rWg+HExyHiHCfgvGP91ZnQUZhIDJPI/J2aqAHmTtIkDEuIjDOeJdCx3V+vtAu+ 01DA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1736195964; x=1736800764; h=mime-version:references:message-id:in-reply-to:subject:cc:to:from :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=qO2YViZm8il4nDX9JseJbZRFAqeiALGsHheIiNc3LqE=; b=oMF6UXLYpEcWgQNEyI2iLKkOBNRfA1q10KdK8f8uuUDKb747+jW+Pv7ihju+VYDkGC yHBhQZrq1xAQUPbDv7NYRiBhtPVH9XG2EKDEIgvFoncVZqVerMqXb3zi83Ti+RRtKUbe 2Yz9fGYDhnqJXVQyT7Ty00MbRVF9UpXu8/Sm6oMQ6r4mm1vJz5Da6UTYXWHk6p4cMIS+ VYBKkXFsxhPbMJOGkv84M+600Lr+gh00sYlLA68Luj8GAiDbQJJUKHG1TwCzEkOin8Bb 0oH47i92tBtZ866ewBQZCZzKbUnosaZQc5OUUbaeoBjxaqxraotuJSr4kVqIQo6JMSrd w+Gg== X-Forwarded-Encrypted: i=1; AJvYcCVRFWVHuRSedc+la5Kv9j9ogvrVTjr3ZQdOne/GoeQ1pbNk7KH7v4L0Qn4CzeYIOq84G2xhuzd4LRWsg0A=@vger.kernel.org X-Gm-Message-State: AOJu0YzOdAOnBpZOsRa1pO2BU5a6mFwSMdUfonLES5lVuH/uS8WlGXuK tTmWm56Vw90+JV1e81QxT4w2V4C2g7v1aCXYGAJJ7nl8/zRf1vqupopoPzH1IA== X-Gm-Gg: ASbGnctcTho1wVoTTj+IMX4i/3g2kdkapGti1pHnfdlmiEV8BVM17leNjzgKSs19jly oBUtd3Ag917F0/XGHTFUWNZZSWqdq8Jn65S5KCcAAUZpOYPET0aOIwBsQfWQ+53g3LQ5jYNwYb0 x8R8f/HfodeFF/MA3QFubxw6rrE3gvnuBwDsiyu+pyP09whDDmbpkS6pTzMuQ+AjfA9CtYeraT7 7pA6sGJgM/EEksAcTOGkv23baETOxjeYH9RDy/GphUt2XpEWqBkTr27S7mxABvtCRkc3iM0W/GV XTmJ1Bzkyt8= X-Google-Smtp-Source: AGHT+IE1XWLGlDP0RmDHgECHZOwekwWGt4X7P/RkpixXfZTU0qeuNkLJQ7GQleURprl3PCgLNlRn9w== X-Received: by 2002:a17:902:c40f:b0:216:405e:8e2 with SMTP id d9443c01a7336-21a7ae15a69mr298775ad.27.1736195963962; Mon, 06 Jan 2025 12:39:23 -0800 (PST) Received: from [2620:0:1008:15:bee6:75f5:6b93:9881] ([2620:0:1008:15:bee6:75f5:6b93:9881]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-2f4478aaa74sm34337736a91.45.2025.01.06.12.39.22 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 06 Jan 2025 12:39:23 -0800 (PST) Date: Mon, 6 Jan 2025 12:39:22 -0800 (PST) From: David Rientjes To: Ingo Molnar , Peter Zijlstra , Juri Lelli , Vincent Guittot cc: Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Valentin Schneider , linux-kernel@vger.kernel.org Subject: [patch 2/2] sched/debug: Remove need_resched ratelimiting for warnings In-Reply-To: <77e42990-0ea3-fc53-8051-6856a92ad4d0@google.com> Message-ID: References: <77e42990-0ea3-fc53-8051-6856a92ad4d0@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII The need_resched warnings are controlled by two tunables in debugfs: - latency_warn_ms - latency_warn_once By default, latency_warn_once is enabled. Thus, a need_resched warning is only emitted once per boot. If the user configures this to not be the case and changes the default, then allow the user to also control the threshold through latency_warn_ms that these warnings trigger. Do not impose our own ratelimiting on top that may make it appear like there are no cases where need_resched is set for longer than the threshold. Signed-off-by: David Rientjes --- kernel/sched/debug.c | 5 ----- 1 file changed, 5 deletions(-) diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c --- a/kernel/sched/debug.c +++ b/kernel/sched/debug.c @@ -1293,11 +1293,6 @@ void proc_sched_set_task(struct task_struct *p) void resched_latency_warn(int cpu, u64 latency) { - static DEFINE_RATELIMIT_STATE(latency_check_ratelimit, 60 * 60 * HZ, 1); - - if (likely(!__ratelimit(&latency_check_ratelimit))) - return; - pr_err("sched: CPU %d need_resched set for > %llu ns (%d ticks) without schedule\n", cpu, latency, cpu_rq(cpu)->ticks_without_resched); dump_stack();