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 739BC335080 for ; Thu, 5 Feb 2026 22:10:31 +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=1770329431; cv=none; b=JNcCKz3DtUmfjXYfABJyKcUNY9hjtDMYa9xjbTdrtrkdcBJzfu/Ez/OMyax9Hn0q8XRneSzfQ/EGcZasm91yhL4IOaP2XxcWcMHoNB4LM/xJaOsyJSQOFvcLCqrpaAB45RG2/WIq/AynItvcANETHqykRdG//SC0OTxFTQRLvfY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770329431; c=relaxed/simple; bh=AOQCLD5sA7rqxsb0SveuZEUCbD58urXVrqYvK8EWa0Q=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=jN3wrUUynxiLgFw+xTqtMC5oG4C4XIdVt1r6lj7fjkhSkTF0LCkkmAbLwvzDtIwhGlxnNHGougenJSgjb8EF4S2ODS847N5uDH+frGm9D+bygH0AbZYCbMDYJFEkQskSt7JIl54fEyDTd3Wt2TjPPwimKMuw++8HGNdpRB8SbUw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=aGE2lgFU; 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="aGE2lgFU" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 38839C4CEF7; Thu, 5 Feb 2026 22:10:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1770329431; bh=AOQCLD5sA7rqxsb0SveuZEUCbD58urXVrqYvK8EWa0Q=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=aGE2lgFUDJjUoYimgx4bSHXEzfRtF4ewhRI7hONQ5wOWHw9iJs4nkRqh1VCQd3rTl pfbtnUOXtAlihEO4CF+iDADkMiEwEzeAZmD4Cfpg0PxHK3ratZW0/p0vze/HpLQt0y 9KqZqZZ1e9owgfJsjzmHo9vCaPOUn/7PCEL5MSuTxWfGMxV4uIpBaDjAR/Ym2sOKxG B9QMX/938nFb5J5DwAn6r5q8U3os+eHi5HGE75I6aYdQWek19tU3R6+mI1NkBkzwYv KJQdSYzMq68q3+l6cxXfo6Dw2mivaeHCFHIz7s1r9sOEblhQOG7bgLdiWUqhiSHenJ DYTbDwlKXZDnw== Date: Thu, 5 Feb 2026 12:10:30 -1000 From: Tejun Heo To: Chuck Lever Cc: jiangshanlai@gmail.com, linux-kernel@vger.kernel.org, Chuck Lever Subject: Re: [PATCH v2] workqueue: Automatic affinity scope fallback for single-pod topologies Message-ID: References: <20260205024912.6753-1-cel@kernel.org> 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: <20260205024912.6753-1-cel@kernel.org> Hello, Chuck. On Wed, Feb 04, 2026 at 09:49:11PM -0500, Chuck Lever wrote: > +static bool __init cpus_share_cluster(int cpu0, int cpu1) > +{ > + return cpumask_test_cpu(cpu0, topology_cluster_cpumask(cpu1)); > +} Cluster boundary == core boundary for a lot of CPUs. I don't think this is going to work. Here are a couple options: - Introduce an affinity level which splits CACHE according to some adjustable heuristics. - Make the NFS workqueue default to WQ_AFFN_CORE (or maybe switch based on some heuristics) or switch to a per-cpu workqueue. Thanks. -- tejun