From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (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 75DF942078; Fri, 3 May 2024 08:53:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.92.199 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714726384; cv=none; b=gUwbWgkBo0v1+DjvP/dN6L+BJF2sHKqVcLKv1QPtc8XU2lwWX2j5VNwFtJFPFvCvtfwhOtShmz109pCUQ44MlLC+Hw5BpeC2ixq5vfrN6BAfoiLwoMentXgtr6UEcJZ7EX2pUvHMtEtOpq9l1JyxR7WUzloSx7kVKLPmX+V2dx0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714726384; c=relaxed/simple; bh=tfIsg2m0rTplnSPTjbZcbaofplOQsoByH+XZniAFybY=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=jiPE+WLTrsZfQDmU6AZ940BYYIobb3M+2DLAiNh97DCPLCRsRV+e7X7L+OUu8UoHgI8QIm3px+OIRVMklsDN+dGg2/W0r90F7ZsnIZAyKMMV+IZv6MFR0Fc7qh20ffAt8PnTwI/IZiTlPULQH2nbTo8vrENWe10psi4wcch+EfM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (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=IK7scVgx; arc=none smtp.client-ip=90.155.92.199 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (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="IK7scVgx" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=hMz32PGVzRagLNUVyXc5cqkcVrop94QJdt3HE/Yw+ZQ=; b=IK7scVgxgViuf5ll8PEndwdTJJ 8VNej+oQcUSk3N4WaIuIm04w4D84WTvu2RRECZt1AiyZWkEompbhdi2HEuzp4cZdaa0FW0RYwDSUw w1cudsaYNJQK9MscRomaEEgkEU14UnlozL1mqIhSrHwc7lMH/knwAwTPEYdlcW+e+QESVEvtdDMKE M8N85xi54qChXfviTPYACczxgyQ7pvibqJrwrX8RGZdyBgd+pd2V+beGqIIapJGKP4cG41dSdJAMf THlfOEEQfAZSZlt5L7A3Zwg1b6ERclkhL4fePFychLCCqmIUTz/y6ahhY0ml1X+MEN8GV7BsNedBC 1TEpXGbw==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.97.1 #2 (Red Hat Linux)) id 1s2oef-00000000UIt-12Pg; Fri, 03 May 2024 08:52:33 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id DD61F309319; Fri, 3 May 2024 10:52:32 +0200 (CEST) Date: Fri, 3 May 2024 10:52:32 +0200 From: Peter Zijlstra To: Tejun Heo Cc: torvalds@linux-foundation.org, mingo@redhat.com, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, bristot@redhat.com, vschneid@redhat.com, ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, martin.lau@kernel.org, joshdon@google.com, brho@google.com, pjt@google.com, derkling@google.com, haoluo@google.com, dvernet@meta.com, dschatzberg@meta.com, dskarlat@cs.cmu.edu, riel@surriel.com, changwoo@igalia.com, himadrics@inria.fr, memxor@gmail.com, andrea.righi@canonical.com, joel@joelfernandes.org, linux-kernel@vger.kernel.org, bpf@vger.kernel.org, kernel-team@meta.com Subject: Re: [PATCHSET v6] sched: Implement BPF extensible scheduler class Message-ID: <20240503085232.GC30852@noisy.programming.kicks-ass.net> References: <20240501151312.635565-1-tj@kernel.org> <20240502084800.GY30852@noisy.programming.kicks-ass.net> 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: On Thu, May 02, 2024 at 09:20:15AM -1000, Tejun Heo wrote: > Hello, Peter. > > On Thu, May 02, 2024 at 10:48:00AM +0200, Peter Zijlstra wrote: > > Can you please put your efforts and the touted Google collaboration in > > fixing the existing cgroup mess? > > I suppose you're referring to Rik's flattened hierarchy patchset. > > https://lore.kernel.org/all/20190822021740.15554-1-riel@surriel.com > > Rik spent a lot of time and energy on it and IIRC one of the reasons why it > didn't get pushed further was the lack of any enthusiasm or support from the > upstream community. > > We can resurrect the discussion on that patchset but how is that connected > to sched_ext? I'm absolutely not taking any of this until at the very least the cgroup situation that's been created is solved. And even then, I fundamentally believe the approach to be detrimental to the scheduler eco-system. Witness the metric ton of toy schedulers written for it, that's all effort not put into improving the existing code. You guys Google/Facebook got us the cgroup thing, Google did a lot of the work for cpu-cgroup, and now you Facebook say you can't live with it because it's too expensive. Yes Rik did put a lot of effort into it, but Google shot it down. What am I to do? You Google/Facebook are touting collaboration, collaborate on fixing it. Instead of re-posting this over and over. After all, your main motivation for starting this was the cpu-cgroup overhead. >From where I'm sitting, you created a problem (cpu-cgroup) and now you're creating an even bigger problem as a work-around. Very much not appreciated.