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 56F85345741 for ; Wed, 5 Aug 2026 14:48:24 +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=1785941306; cv=none; b=UaBYJ3tTbzXzWOMcQwa9rKqkK2AQf15XwjAaZvVe5WRWLp6ulgbTmI/hoiZHQv/h7faCkpCYq7Tahu1HY+pZIAguuH5GjLgf5zdvcdWrL/6Kgq8GGI4ntYqz9LDbiPgWlSJN7BGY2Xg6kN8f1lB6W77zr6Ks7VW/Y+sJHNyGWFk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785941306; c=relaxed/simple; bh=TNWZy6YCwk1Jg/670Yw8+8Dm+5ppwdOabUkzC+QBhQA=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=hjx+96O/iiOrE3Az5ocA5DxWCUH21gtw5bBXBxMWEFG2FCr1mlm8XgU1N+uvenuXuNm6zzYqfvNchP4R7X6XsN2jjYz7CPRqpZrlgLtWPOLVfUCyVDzxdhnC0+xQQZag2la4MSeWKAE70Yrji5czESOI8SlukWzuvB2ZQaap3Rk= 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; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b=j5AFHTTL; 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 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b="j5AFHTTL" 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 3589B153B; Wed, 5 Aug 2026 07:48:19 -0700 (PDT) Received: from J2N7QTR9R3 (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 6F34F3F632; Wed, 5 Aug 2026 07:48:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1785941303; bh=TNWZy6YCwk1Jg/670Yw8+8Dm+5ppwdOabUkzC+QBhQA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=j5AFHTTLzxiQjtqEvFZsht+b9/H6BjM/x3RwHls947twbgJc0VGaenS9OuNnNIJOT mEjbZ+iR1nCYefAMDmIk62GyEXF0p+Wocz/2eB8/qm06XSy16S6U1PRVbyU662kBAt jLhd7uZexScAhraTfyFOENpLJ/diDU8f6Yc/ZhcY= Date: Wed, 5 Aug 2026 15:48:14 +0100 From: Mark Rutland To: "Christoph Lameter (Ampere)" Cc: "David Hildenbrand (Arm)" , Yang Shi , "Lorenzo Stoakes (ARM)" , Linus Torvalds , Ryan Roberts , dennis@kernel.org, tj@kernel.org, urezki@gmail.com, catalin.marinas@arm.com, will@kernel.org, akpm@linux-foundation.org, hca@linux.ibm.com, gor@linux.ibm.com, agordeev@linux.ibm.com, linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Jason Gunthorpe Subject: Re: [RFC v2 PATCH 0/16] Optimize this_cpu_*() ops for non-x86 (ARM64 for this series) Message-ID: References: <25d1e09b-53e4-7cd5-87db-b58437e4e690@gentwo.org> <4887267b-dc26-4c33-96ca-8dff054a0d1f@kernel.org> <69f4cd9c-bd6c-4e5d-b8d1-a7be8408a57a@os.amperecomputing.com> <94c7988a-3ecf-4b26-b0a8-011bdc76283b@kernel.org> <29edec61-8f11-b9b1-3df9-2a51815ee771@gentwo.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: <29edec61-8f11-b9b1-3df9-2a51815ee771@gentwo.org> On Tue, Aug 04, 2026 at 03:35:22PM -0700, Christoph Lameter (Ampere) wrote: > > > That's really all we are asking for. If there is a measurable performance > > difference, great. Share the results or point us at them if we missed them. > > Scanning over the patchset: It seems that you are using a special > instruction that is unfamiliar to me. Which processors support that? Which patch and which instruction are you referring to? There is no information to go on here. Asking on that specific patch would be helpful. Mark.