From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 7BBA84A0F for ; Tue, 18 Mar 2025 00:14:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742256893; cv=none; b=V6D8GPhVikIa4O445K6dh70Jf9fSErOZ/tafwHkIE752k6NS6Yo13fOvWzWLl7iT0dfVRqJx2fye9tvNn1p5/zRUCkyJ0la2gSpysg92J2L9581k7lFWYvS1TrS8CLDpfuKorUSouzmhmyuSzAOy+v/PUodKtv245uLxws+8Rpw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742256893; c=relaxed/simple; bh=tUNzi0RCn6yGzZRiFcxsD3qbSKdqAzvcr2XZm4pvu2E=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=VXiS9Sg6s9y7LFDKNqkyg4BD2it9mMw6ytBbooHcucO8lpBU3MAybZX11iWTT9FQSwAdGgpZnA7P+q0FTYiatAVVTlC1hniz+CKxCOooD6bzPykkqZVYNiURi/KDYoC++lkCoRHk+FocBvMuP94dH4QVwj2w0mYDExHB8UGW0FE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Ei0ygVdT; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Ei0ygVdT" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D55EBC4CEE3; Tue, 18 Mar 2025 00:14:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1742256893; bh=tUNzi0RCn6yGzZRiFcxsD3qbSKdqAzvcr2XZm4pvu2E=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Ei0ygVdTWhdBoUF3/iBDld2BTF6Ag3UkjYztm++DS2DZV7Qh2enCwFOVGdHo9IlyE 4vkSTtdXVrAL+q5zq7UtED72N6Hqdpv0niwMmf2KkMj26QAgeELR+wBj671meFDXVT PqIK6r3F4Gb59DVicRSAe9Npo3/7m9U91oS2v3soqqBmi5bPoOuvqJkHCnqTuN03vm HyW5DzfoOdf6iKZCTS3IbAEsFTb/LNt7IPQHbtespcNfJoqsll+AdUWX8mgI9I8wD/ 54cGXZ7+CUiNwK6EDuLAiKS7/0quSUeEc+700xkS5XGgJpBBiwYFBKKWCBo/5jnYWb DagkznOLFPORg== Date: Mon, 17 Mar 2025 14:14:51 -1000 From: Tejun Heo To: Libo Chen Cc: Joel Fernandes , linux-kernel@vger.kernel.org, David Vernet , Andrea Righi , Changwoo Min , Ingo Molnar , Peter Zijlstra , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Valentin Schneider Subject: Re: [PATCH RFC] sched_ext: Choose prev_cpu if idle and cache affine without WF_SYNC Message-ID: References: <20250317082803.3071809-1-joelagnelf@nvidia.com> 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, Mar 17, 2025 at 05:12:25PM -0700, Libo Chen wrote: > Just as Peter said, this is whole wake affinity thing is highly workload > dependent. We have seen cases where even if there are idle cores in the > prev node, it's still beneficial to cross the NUMA boundary. Will it make > more sense to have the BPF scheduler implement/alter some of logic here so > it can fit to different workload? Oh yeah, multiple SCX schedulers already implement their own select_cpu(). This discussion is just around the default implementation which can be used if a BPF scheduler doesn't want to implement its own. Thanks. -- tejun