From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 12E701537C9 for ; Wed, 11 Sep 2024 11:50:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726055412; cv=none; b=mQHXkESBpvpcd8VNpulKH4AD996M6ZeYfmq9CkZATOrqulcvtOoMjHZ5Qi7n6kcV1DzcPYez7z60D1UwXjRx++nEK3XRCvO2a1MPfUNirlKGwUL3D9XUtVk6mGerqzC/+FaqUZf94lJEjoOb2tPs0SGiqNvnIKY5SGH0ZK7YdNA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726055412; c=relaxed/simple; bh=edkIKEk/zcSVt0K3ytWmjSzmlNzdB5TadLx9PEuf6rc=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=jhuoYiOfkWEZDTEawvYJru6Lnenpd5EjMBSqlWMcrPohMgMuWd1Reg3kTy/0vVWEwoJK5v6TWdfRV5qHr0SP9hpvB+8cMMJol2t92G0vWeJN7IkDUkHhMiPOhlHRk9aipEKWvGV1YB9WrGg+SHSjAGbjOepcxtDbAS8KHgGrQG4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id D82AADA7; Wed, 11 Sep 2024 04:50:38 -0700 (PDT) Received: from [192.168.178.6] (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 0A67B3F66E; Wed, 11 Sep 2024 04:50:06 -0700 (PDT) Message-ID: <4e2ad815-a8f8-4800-b389-6b8a79bcf04e@arm.com> Date: Wed, 11 Sep 2024 13:49:59 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 10/24] sched/uclamg: Handle delayed dequeue To: Peter Zijlstra , Mike Galbraith Cc: Luis Machado , Vincent Guittot , Hongyan Xia , mingo@redhat.com, juri.lelli@redhat.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, vschneid@redhat.com, linux-kernel@vger.kernel.org, kprateek.nayak@amd.com, wuyun.abel@bytedance.com, youssefesmat@chromium.org, tglx@linutronix.de References: <20240905145354.GP4723@noisy.programming.kicks-ass.net> <20240906104525.GG4928@noisy.programming.kicks-ass.net> <8d0d01b9-a430-49cc-93a5-67b4d68aa35c@arm.com> <20240910140524.GH4723@noisy.programming.kicks-ass.net> <52ca4cea-8f65-434e-af17-e4bf664d9488@arm.com> <20240911084528.GJ4723@noisy.programming.kicks-ass.net> <4fde8f26a9aeaeafda15b81bbb17b0ffc96941f0.camel@gmx.de> <20240911091328.GM4723@noisy.programming.kicks-ass.net> From: Dietmar Eggemann Content-Language: en-US In-Reply-To: <20240911091328.GM4723@noisy.programming.kicks-ass.net> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 11/09/2024 11:13, Peter Zijlstra wrote: > On Wed, Sep 11, 2024 at 11:10:26AM +0200, Mike Galbraith wrote: >> On Wed, 2024-09-11 at 10:45 +0200, Peter Zijlstra wrote: >>> On Wed, Sep 11, 2024 at 09:35:16AM +0100, Luis Machado wrote: [...] >>>> So probably an unexpected decrement or lack of an increment somewhere. >>> >>> Yeah, that's buggered. Ok, I'll go rebase sched/core and take this patch >>> out. I'll see if I can reproduce that. >> >> Hm, would be interesting to know how the heck he's triggering that. >> >> My x86_64 box refuses to produce any such artifacts with anything I've >> tossed at it, including full LTP with enterprise RT and !RT configs, >> both in master and my local SLE15-SP7 branch. Hohum. > > Yeah, my hackbench runs also didn't show that. Perhaps something funny > with cgroups. I didn't test cgroup bandwidth for exanple. Don't see it either on my Arm64 Juno-r0 (6 CPUs) with: cgexec -g cpu:/A/B/C hackbench -l 1000 We are checking the Pixel6 now.