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 1D1E23A1CD for ; Fri, 31 Oct 2025 11:32:18 +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=1761910341; cv=none; b=YjDLsyRsJq5OK/2aKeb1ILz/y+JM88zQTuaZ9tXs4rUzj+D1BEAnP7pYmawi266FiXjZculAFrIkHlEF0GaUGZ02uOAMskUGWSQMy3ibGuYN6kpvk/5T1SDv3yed8ul2c04GBDVAoht98p5SXbdTXy5IpCDZ+ahEv1LBd0ccnCg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1761910341; c=relaxed/simple; bh=FlvaNo2diJDK7tG97oUZUZuXx71KGSMPgDS4fXcHkmE=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=cF55isSrbH758vVw/1C3Z42prbgtULtU08e1DQqtR2ucuzTlcFR6U3fiAHrxQRT/Iv5TdNMnuhog5voCHuxjrXlNchm1OQuzTpr9F6GGGY/ibPalRr6rI9BPN+CBmTreHVsq/Dr9kPu/FU2hSOM54UJIUxL+B+cbR1C7YEyuUGU= 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 4DBE91595; Fri, 31 Oct 2025 04:32:10 -0700 (PDT) Received: from [10.57.86.182] (unknown [10.57.86.182]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 4692F3F66E; Fri, 31 Oct 2025 04:32:15 -0700 (PDT) Message-ID: Date: Fri, 31 Oct 2025 12:32:13 +0100 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] sched/fair: Prefer cache-hot prev_cpu for wakeup To: Shubhang , shubhang@os.amperecomputing.com, Ingo Molnar , Peter Zijlstra , Juri Lelli , Vincent Guittot , Steven Rostedt , Ben Segall , Mel Gorman , Valentin Schneider , Shijie Huang , Frank Wang Cc: Christopher Lameter , Adam Li , linux-kernel@vger.kernel.org References: <20251017-b4-sched-cfs-refactor-propagate-v1-1-1eb0dc5b19b3@os.amperecomputing.com> Content-Language: en-GB From: Dietmar Eggemann In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 30.10.25 17:35, Shubhang wrote: > The system is an 80 core Ampere Altra with a two-level > sched domain topology. The MC domain contains all 80 cores. Ah OK. So I assume the other SD is CLS with 2 CPUs? Does this mean you guys have recently changed the sched topology on this thing? I still remember setups with 2 CPUs in MC and 80 CPUs on PKG. If this is the case, is: db1e59483dfd - topology: make core_mask include at least cluster_siblings (2022-04-20 Darren Hart) still needed in this case? > I agree that placing the condition earlier in `select_idle_sibling()`> aligns better with convention. I will move the check (EAS Aware) to the > top of the function and submit a v2 patch. I can't imagine that you run EAS on this machine? It needs heterogeneous CPUs which you shouldn't have. Looks like that Christian L. was asking you already on your v2. [...]