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 71E96349AF4 for ; Fri, 20 Mar 2026 10:24:48 +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=1774002293; cv=none; b=LIwdbckyvaiMQ28xi9dSnVbnLi6cHfwyja7lB70Tq4wPbzX5Z7KoqrbLxSFT4nfPUWJSpTIXp+N3WdlizeMZlW/5anwZAgAETAaxiKg7/HKsaJpAkvj4D012sN7Gz3BmY+FXsFnhnPAzUGQ39DmCbPge3oxeRWkRZYXRKoRlBzQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774002293; c=relaxed/simple; bh=IbmCfaJUG3WBiglhrG/EFkHUSIKSp5uaNbnIvTWXZeU=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=gxT6rjluaXReyPwWRgg9vZuZypoLO4YyJUIX7FGddtDXZ76bC7b7RrrUSEkYcDgno4GIk40U01vggc+H+CMt2zGHk4CemgltPxigV1CECDrCMDiwXn/t2Rcjp5wuLsqJvEPMDOKJhvon07Jtk2o78Ss+/S2fkg/AmKT9LaohHQw= 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=ntEZ58jE; 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="ntEZ58jE" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; 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=IbmCfaJUG3WBiglhrG/EFkHUSIKSp5uaNbnIvTWXZeU=; b=ntEZ58jEksLImiKHxG6ZVL7JRE v7jwZQbC1DUXFujhy9FEJ7sTbJSw/HwbY2UNbSAPTZdyqRICcbWR/AEowzuToRoX0X7ldvAiVKemh P6OJPiWbttoJgTQY3pJZvX7+FasPRjcxqasnQtorztpH+UXSPlTrvhGAW7VVBCI3wcdNtZ79Rdr/2 mbSuM0DXRZOLqj1R1ugdaC8/jaSHnoPIk3ZNd+8bXRvuwuziJ4ppAVnh1Qn/gBceg6NOYfl0qvZCv oTbI5HsCgvOLbav1TujAlTeBkA0MA9C7Ae6A0GpyWxLU7zNOV11zVghRQCT9MtET6Q449fz/gzyvy 8/WYSEOA==; 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 1w3X25-00000007c6Z-3fvB; Fri, 20 Mar 2026 10:24:45 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id 50BB8302FFB; Fri, 20 Mar 2026 11:24:40 +0100 (CET) Date: Fri, 20 Mar 2026 11:24:40 +0100 From: Peter Zijlstra To: Pan Deng Cc: mingo@kernel.org, linux-kernel@vger.kernel.org, tianyou.li@intel.com, tim.c.chen@linux.intel.com, yu.c.chen@intel.com Subject: Re: [PATCH v2 3/4] sched/rt: Split root_domain->rto_count to per-NUMA-node counters Message-ID: <20260320102440.GT3738786@noisy.programming.kicks-ass.net> 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: On Mon, Jul 21, 2025 at 02:10:25PM +0800, Pan Deng wrote: > As a complementary, this patch splits > `rto_count` into per-numa-node counters to reduce the contention. Right... so Tim, didn't we have similar patches for task_group::load_avg or something like that? Whatever did happen there? Can we share common infra? Also since Tim is sitting on this LLC infrastructure, can you compare per-node and per-llc for this stuff? Somehow I'm thinking that a 2 socket 480 CPU system only has like 2 nodes and while splitting this will help some, that might not be excellent. Please test on both Intel and AMD systems, since AMD has more of these LLC things on.