From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794322370; b=exTEJ+8rDxbvJzUrHhyqa68vcK+Pu2hu+8MlVQnfouBN5CT+yrNrgY5QUaM/aO9bn38X GykGeK8BKl5zZ2N8u4YLN+KCAV8hj5X/2S45rM5tf/qbzqjup7g9tRxwmyOEp9PBzEg2+ L97aoAtDuk1RJmCKr+0fXvAJ2mOduDxY34Xa7JiJtDiL7k5bEt3lj7DLZ01/OLZ0OaEBa CB1+Ql+AGx+vbblGW9UuoqqZtwS4ZOm4cx9H59cgq2J1TFkFYI7YyOGezn2T0ONBqg4PX 1/+9v/W0U65T9DDL/YIm3QBZ3ueg2tdpjZvB1txKTO0TuH+XFf6r3VEJg1BpN5cEIRQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794322370; h=Received:DKIM-Signature:Date:From:To:Cc:Subject:Message-ID: References:MIME-Version:Content-Type:Content-Disposition:In-Reply-To; bh=KjNKU0fVTO1GwsQf4N77ndWDLlPg8PdsmZT2hfApWPE=; b=kzY1HkkCKnG3c9eLAM/Bkxs0cvxgSj53utF5Ow4HjH9xaXfAQS00XS7O9j2kLkNr73g7 gEvZ8yDblEoOVrQVVJrtsrK8jOZt4UYhZ2J6PglU6rHUZmlCEiixX/jan+ZmLkeoPT0T4 WbUbbpi6ytgPDBglL73guPpsrIeVWahkvvNEDj3QUc5rSR/MOMh8i+Yu09QUMR5QSTJTq gLvfrdIACxqGJCcx352vZc82ENfg5p5LsXbb5ZgXj44BuDWUzMQOYjLxvHWXesx2s1Uon TQtbDsjVPVDwOWhx5t3CV/Wshm6FhzGSmfU0NI35t0uP56/IK9iV9W5IHmcaunWyKIA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=ir9ZLK3P; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 87C0F606A31C; Tue, 10 Nov 2026 14:52:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=ir9ZLK3P Received: by smtp.kernel.org (Postfix) with ESMTPSA id 52E291F0089F; Tue, 10 Nov 2026 14:52:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794322370; bh=KjNKU0fVTO1GwsQf4N77ndWDLlPg8PdsmZT2hfApWPE=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=ir9ZLK3PpkfzDHwBcrLGOXj9EpS3CyRkUiWe2WwPnXWGe9MH7GhS0D6BtRe4YJbHS BPWDdz6H34G8sRDEWFesNvtxhFSktyx4dL89CZlAObyY2+4zj+YpmdRZE4zYPYzlJN EL7RwDR/T7DATHbxcGSS8hRjxDb316TtTTckKTKgWIK4iGZCB98im3bPBJB5r0hb7L VsHPwUXFS83jzWgZtIgh/mqO7VaoEDxb5nwxXqHePDGnZbghwcb+WtWNAhpRPlFWH0 jGV9L3oUmue0lg5M7GyOBz+3YXmbdy++CeGlfIg/huEG/6o8pU9vyl5gl+SzYbNO0K hFyUOG4XEhrfQ== Date: Tue, 10 Nov 2026 14:52:43 +0000 From: "Lorenzo Stoakes (ARM)" To: Seunghyun An Cc: "linux-mm@kvack.org" , Andrew Morton , David Hildenbrand , Vlastimil Babka , "Liam R . Howlett" , Jann Horn , Pedro Falcato , Matthew Wilcox , Jan Kara , Dave Hansen , Suren Baghdasaryan , "linux-kernel@vger.kernel.org" , "linux-fsdevel@vger.kernel.org" Subject: Re: [PATCH 0/2] mm: avoid redundant reads of the vm_refcnt cacheline in anonymous faults Message-ID: References: <20261110000002.1834454-1-san55@wisc.edu> X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Tue, Nov 10, 2026 at 02:34:31PM +0000, Seunghyun An wrote: > Thanks for taking this on. > > I should have disclosed the LLM involvement up front, and I'm sorry > I didn't. I came across this while researching the performance of the > anonymous fault path and worked with Claude to investigate and quantify > it. Claude also drafted the code and changelogs. > > My main aim was to report the findings to the community. In hindsight, > a plain report would have been a better way to raise it. I wanted to share > the measured effects, especially on EPYC given the higher cross-CCD > coherency penalty, and offer a possible way to address them. > > I'd be glad to collaborate on measurements for your series and any > follow-up work in this area. Thanks! I will cc- you on the patch, and if there is any remaining issue we can chase that down. And of course credit you on the patch as reporter! :) -- Cheers, Lorenzo