From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BA396261595 for ; Fri, 7 Nov 2025 16:18:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.50.34 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762532302; cv=none; b=AqcadNQhgC+YaSFkA5G+CX/YEkUOtkE6T1iKGVhjLHWvxttelh9xYT+LxVsV+jHbL/MrTTaVLlAemtT/T8Z1JZYpW1k/RjJrqA6prJ/TpKucYshCYbkx3lGkDpV+Yc64rXoHDPpVLkg/77OhE/ve5iGv35rE+sOp1KBOzRNqVQw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762532302; c=relaxed/simple; bh=X56xHjmK09pjaEsSOZBpxYflqOx5s/ONZ13vOeBhZhI=; h=Message-ID:Date:From:To:Cc:Subject; b=eR4z35tha00jTlSZyDjiUY7g9uUrwKa4/IMch0ue20481mGGXCQNMdBMmfNadBPLGyfGpE5Fyu0R+NGvhVrODQplfth8SkHrINiBPU2hzbX8xc6Abo1b/Blc59403VR6sVzo+yfP+RS07YyVaxl8TDPbcCo0v51i0kcDTNIH8PU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=p2vhcV9E; arc=none smtp.client-ip=90.155.50.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="p2vhcV9E" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Subject:Cc:To:From:Date:Message-ID: Sender:Reply-To:MIME-Version:Content-Type:Content-Transfer-Encoding: Content-ID:Content-Description:In-Reply-To:References; bh=ZB2h4dGhcK9TxkRdVGaERfGCO6fwXtDuysjkKY0+IbQ=; b=p2vhcV9EgbaOT94SfbmTSDlHla kRfMeC9cr1BgeWw9pc4gQ1Wc6UPEUeRty7cov04Yhe0i8DJVe30UcmJAluo1tytXukTs/UnC/MJ4g 76uVbEKU3aapEGoJ8PVr6GYEH+yQkMJrv0gukEqQLdvBvJMmf4OO4Ss3xcCwR52CBhrkcJ/XtMUtQ baFW+JfD1xvkc8qNN3ggcuMymqVY5Qyi7zNVevBRXs1g7cFiOKvAgDHjLeiGGoLXhS8Y+k6XFhLU/ 5z+LVIZSa9cUMba567WyBw2bJv+tsRQ1rXVfjd0GNT84gz0hBgNKl92W6AHiP5UHdT8F/JL7rCU+o hVREb1pw==; Received: from 77-249-17-252.cable.dynamic.v4.ziggo.nl ([77.249.17.252] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.98.2 #2 (Red Hat Linux)) id 1vHPA8-0000000DUTK-0Mo9; Fri, 07 Nov 2025 16:18:09 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 0) id EE7D63003C4; Fri, 07 Nov 2025 17:18:07 +0100 (CET) Message-ID: <20251107160645.929564468@infradead.org> User-Agent: quilt/0.68 Date: Fri, 07 Nov 2025 17:06:45 +0100 From: Peter Zijlstra To: Chris Mason , Joseph Salisbury , Adam Li , Hazem Mohamed Abuelfotoh , Josh Don Cc: mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, vschneid@redhat.com, linux-kernel@vger.kernel.org Subject: [PATCH 0/4] sched: The newidle balance regression Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Hi! So most of you ran into Chris' commit 155213a2aed4 ("sched/fair: Bump sd->max_newidle_lb_cost when newidle balance fails") [*] And I posted a patch with a few alternative options. And while I've heard back from a number of you, indicating that NI_TARGET (the effective revert) works for you. Not many tested TARGET+RANDOM (thanks Adam!). In my limited schbench testing that combination isn't horrible, and per Adam that combination also doesn't suck for him. Chris, could you please see what this does for your machines with your actual workload? Anyway, here are a few patches that basically do the revert and introduce the proportional newidle balance -- the NI_TARGET+NI_RANDOM equivalent. Also at: git://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git sched/newidle Please all, give it a whirl. Hopefully I didn't wreck it, its Friday after all :-) [*] https://lkml.kernel.org/r/006c9df2-b691-47f1-82e6-e233c3f91faf@oracle.com