From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ej1-f44.google.com (mail-ej1-f44.google.com [209.85.218.44]) (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 AFF3A168C6 for ; Fri, 12 Jan 2024 21:04:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linuxfoundation.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="dUNfJu8+" Received: by mail-ej1-f44.google.com with SMTP id a640c23a62f3a-a2bdc3a3c84so360468566b.0 for ; Fri, 12 Jan 2024 13:04:33 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=google; t=1705093472; x=1705698272; darn=vger.kernel.org; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=379NH/DRc7y5/q+wxZXouxXkcoZV1s6DfMkXYqpqv6U=; b=dUNfJu8+IwJI6uVWkHBf835b29azG43IM4mgl1S8bvb/IwOqwV4Oce0TZhzaoRlvzs TPcTgd36pSvBfSQVONk5/ACGPDC3KOBAwALpziZZcyOIuJ4waYiQzOWikANnQTKCto+B PuFw1/itzqZQQAMkxbqh3rmvos8Rox8k5AOYo= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1705093472; x=1705698272; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=379NH/DRc7y5/q+wxZXouxXkcoZV1s6DfMkXYqpqv6U=; b=AKhEuyD4N/ojzkFjzxa8oBO3SNnzD1q5/zC0c88YfIwGETEO3cJtVWxJy4VVKDZgvV msNA/cyd8JTL6sy3WOiTVHJVCW39BmVoZw7ciArh6wRwFHyu5MdNQ8/uDQWHuqONQoCo 18NvbT6dB0adhUti00zmY5teyDBDvoTt1SCGPaJSSW6df5iEb8ev5aO+ugWNZDjPo6OU NorvgCaeAtF71a5Jz/LvwQ0yFvCSz/KP4KJg/idc3EMaGqJGked/G9EuzroMnM7klpJP cL/zUnmYxZ/aW4KgjuAhSXtbDxBjpyYHPx7lW3II9ng5FiJRV5Pxj/8kAmOTCzKbWfc8 4PSQ== X-Gm-Message-State: AOJu0YyPhCeqF3C+oe50f3lxWfNInvid58RvBG2fRnQR7fX8nQaXEI1j iuFeFZfwsBTPoZ/E6llqukqNEexv8gCehXF5ej4LbucXiaWw/jtD X-Google-Smtp-Source: AGHT+IHpfKwGE0RuBm8gwYeBN1h68b57WCP8g18TVBhZjQ5X3jwuzmbnNmiV5RJgloyaxWg0VzAfhQ== X-Received: by 2002:a17:906:1e89:b0:a2c:2094:5d46 with SMTP id e9-20020a1709061e8900b00a2c20945d46mr924231ejj.81.1705093471909; Fri, 12 Jan 2024 13:04:31 -0800 (PST) Received: from mail-ed1-f48.google.com (mail-ed1-f48.google.com. [209.85.208.48]) by smtp.gmail.com with ESMTPSA id ga25-20020a170906b85900b00a272de16f52sm2130663ejb.112.2024.01.12.13.04.30 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 12 Jan 2024 13:04:30 -0800 (PST) Received: by mail-ed1-f48.google.com with SMTP id 4fb4d7f45d1cf-558b5f4cf2dso1787107a12.2 for ; Fri, 12 Jan 2024 13:04:30 -0800 (PST) X-Received: by 2002:a17:907:960c:b0:a28:f5bf:ea68 with SMTP id gb12-20020a170907960c00b00a28f5bfea68mr1160474ejc.58.1705093470093; Fri, 12 Jan 2024 13:04:30 -0800 (PST) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 References: <4405adb5-0b16-4716-9542-47d8bb1737ee@arm.com> <20240112181805.bjvrkvvkszdfa7co@airbuntu> In-Reply-To: From: Linus Torvalds Date: Fri, 12 Jan 2024 13:04:13 -0800 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [GIT PULL] Scheduler changes for v6.8 To: Vincent Guittot Cc: Qais Yousef , Dietmar Eggemann , Ingo Molnar , linux-kernel@vger.kernel.org, Peter Zijlstra , Thomas Gleixner , Juri Lelli , Steven Rostedt , Ben Segall , Mel Gorman , Daniel Bristot de Oliveira , Valentin Schneider Content-Type: text/plain; charset="UTF-8" On Fri, 12 Jan 2024 at 12:49, Linus Torvalds wrote: > > All cores stay at 2.2GHz (ok, so there's noise, but we're > talking "within a couple of MHz of 2.2GHz"). Note: that is true also when every CPU is fully loaded and I do a real full build. So the "empty make" is just my quick test that happens to be single-threaded and should take just 20s. All my real builds slow down too, because all CPUs stay at the minimum frequency. And I just verified that Ingo's revert that only reverts two commits (commit 60ee1706bd11 in the tip tree), makes things work correctly for me. Not surprising, since the bisection clearly pointed at just commit 9c0b4bb7f6303c being the one that caused the issue, but I decided to just double-check anyway. So with that revert, for the single-threaded case I see 4GHz+ numbers (they spread from a single CPU to multiple CPUs once you run the benchmark a few times). And then when I run a full parallel build (rather than the single-threaded empty one), the frequencies drop to ~3.85GHz for the all-cpu case. Linus