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[31.46.243.254]) by smtp.gmail.com with ESMTPSA id ov18-20020a170906fc1200b00a2a184687dasm443865ejb.31.2024.01.11.03.09.25 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 11 Jan 2024 03:09:26 -0800 (PST) Sender: Ingo Molnar Date: Thu, 11 Jan 2024 12:09:23 +0100 From: Ingo Molnar To: Linus Torvalds Cc: Vincent Guittot , 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 Subject: [GIT PULL] scheduler fixes Message-ID: References: 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 Content-Disposition: inline In-Reply-To: * 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! 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(-)