From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f181.google.com (mail-pl1-f181.google.com [209.85.214.181]) (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 8144715E88 for ; Thu, 11 Jan 2024 13:04:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linaro.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linaro.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="e6JEhf0D" Received: by mail-pl1-f181.google.com with SMTP id d9443c01a7336-1d3ef33e68dso37125185ad.1 for ; Thu, 11 Jan 2024 05:04:16 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1704978255; x=1705583055; 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=mJye1HwRZXqiDXVZCClxaEgybA810vZVpEjfXbsfFJs=; b=e6JEhf0DE1R6mJWacHwY1y5ZyhbIVbMeHL3r4HLo/FmxsLISWxZ+y1/u1pj6Ih/O0W ati7Yjy3q8NTDd7cpXRq8Ul3nKhf0EaTxKm/p4gLUKWETOC1b0fGlIxllFBmL6eRKRnI /CSA/sH9eRbl9x3ZBI5P8Mqox0jyXHJEqR3lt7ZzKbeXxxalsAWNS7Xbo1nYAcJDXjDQ xyZJJ64pBsul1ppK6sOP6G+6WgC7plspBET6y3cOHRZcXu7TPyCEi1P3S9PAv/Hb7URM fNdDx3wGRTbAQUSYSjTed77kzuFwXlQHQ588oMqmSTwVVmodOmxHai/LX/G6KfiKg2K7 x9Eg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1704978255; x=1705583055; 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=mJye1HwRZXqiDXVZCClxaEgybA810vZVpEjfXbsfFJs=; b=OgbCF98q4EYtm+Zd2WkE88Rl1MFgg7EPhGx2vqQ1IbjM4glMXAOLEHfOBTCrScDuzs HC/EfGUMC8pD5Fpoug1niS02ZttR4YobBEQGqN+CDTg1BsLbzrKIF0m35l8EfNVj/QV0 MmGu7NVJ+36uqDcc2nRMC/xnEqTgapMMAAjBy7ZkEdAGk+csvn7jX3xwvZlVQSv0CMWT yd3TqtQcGWUoE1bTBkdOHDeOiEKgRtgKBnTQdE7IA8Z8cQyPwEkCeC4sjwDnFm4Y39aO 2uaSfi72qxGDNQoUQwH8PLOFBIt5ty+nqqNMx1nQ4gdJVoBCQ7MTSkdzf70iwW5euUj+ uGjA== X-Gm-Message-State: AOJu0Yx+foPjy963ki6LMs2JKRISZcTKDY+3n28cbs2GyIec97bl/PqH NnoykrIChKe9JIZLvKovHXx53he6zttbFMx0iwXP0YP1YL/6wg== X-Google-Smtp-Source: AGHT+IEIWU162vz5BVssaLQ0v5ixlNOrYXMwBNBuJPvkNECOBriOK+cjfvlgUUjSWppOSEVExQD4wxH6SdVKIFrJy18= X-Received: by 2002:a17:902:c3d1:b0:1d5:6b6c:1add with SMTP id j17-20020a170902c3d100b001d56b6c1addmr1014391plj.28.1704978255603; Thu, 11 Jan 2024 05:04:15 -0800 (PST) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 References: In-Reply-To: From: Vincent Guittot Date: Thu, 11 Jan 2024 14:04:04 +0100 Message-ID: Subject: Re: [GIT PULL] scheduler fixes To: Ingo Molnar Cc: Linus Torvalds , linux-kernel@vger.kernel.org, Peter Zijlstra , Thomas Gleixner , Juri Lelli , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Daniel Bristot de Oliveira , Valentin Schneider Content-Type: text/plain; charset="UTF-8" On Thu, 11 Jan 2024 at 12:09, Ingo Molnar wrote: > > > * Linus Torvalds wrote: > > > On Wed, 10 Jan 2024 at 14:41, Linus Torvalds > > wrote: > > > > > > It's one of these two: > > > > > > f12560779f9d sched/cpufreq: Rework iowait boost > > > 9c0b4bb7f630 sched/cpufreq: Rework schedutil governor performance estimation > > > > > > one more boot to go, then I'll try to revert whichever causes my > > > machine to perform horribly much worse. > > > > I guess it should come as no surprise that the result is > > > > 9c0b4bb7f6303c9c4e2e34984c46f5a86478f84d is the first bad commit > > > > but to revert cleanly I will have to revert all of > > > > b3edde44e5d4 ("cpufreq/schedutil: Use a fixed reference frequency") > > f12560779f9d ("sched/cpufreq: Rework iowait boost") > > 9c0b4bb7f630 ("sched/cpufreq: Rework schedutil governor > > performance estimation") > > > > This is on a 32-core (64-thread) AMD Ryzen Threadripper 3970X, fwiw. > > > > I'll keep that revert in my private test-tree for now (so that I have > > a working machine again), but I'll move it to my main branch soon > > unless somebody has a quick fix for this problem. > > Thanks a lot for bisecting this, and ack on the revert in any case, these > are relatively fresh changes that clearly didn't get enough testing - sorry! b3edde44e5d4 ("cpufreq/schedutil: Use a fixed reference frequency") is linked with other patches. I can provide a clean revert of only : f12560779f9d ("sched/cpufreq: Rework iowait boost") 9c0b4bb7f630 ("sched/cpufreq: Rework schedutil governor performance estimation") if the fix that i proposed doesn't work: https://lore.kernel.org/all/ZZ+ixagkxRPYyTCE@vingu-book/ > > I also made the revert in sched/urgent & added a changelog, which you can > pull from: > > git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git sched-urgent-2024-01-11 > > # HEAD: 250ce3c1169743f3575cc5937fccd72380052795 Revert "sched/cpufreq: Rework schedutil governor performance estimation" and dependent commits > > Revert recent changes to the sched_util logic, to address a bad > performance regression that increased kernel build time on Linus's > 64-CPU desktop system substantially. > > Lightly build and boot tested. > > Thanks, > > Ingo > > ------------------> > Ingo Molnar (1): > Revert "sched/cpufreq: Rework schedutil governor performance estimation" and dependent commits > > > include/linux/energy_model.h | 1 + > kernel/sched/core.c | 90 +++++++++++++++++++++++----------------- > kernel/sched/cpufreq_schedutil.c | 90 ++++++++++++---------------------------- > kernel/sched/fair.c | 22 ++-------- > kernel/sched/sched.h | 84 +++++++++++++++++++++++++++++++++---- > 5 files changed, 160 insertions(+), 127 deletions(-)