From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 EB01A3502A5 for ; Wed, 5 Aug 2026 06:11:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785910298; cv=none; b=gOAoi3i3Hc7I5N5xaJCCSn1iFj3P+x8xvOZR3GGpI5KIWPBBxITQfVWvQyeRppJxSgO8kjT2PWZ4lUGGPFbXOFp0lQ9cHgdfhBRvRVIKmKfkPkTIp4/lURAmkKUN4LTvdo1QX/o1vlwC13+7Pryb4ye30VI9fFDFgGlBY0ic2Vc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785910298; c=relaxed/simple; bh=NMAHtFrrYtk9Ejb7uQiSG+41boZW0hfrw1GtN/PWFuU=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=ZiyziFbdWVIrJxJm2Hk4JXl9tet2iISKGpmfCGLQ5aIWpfxwSZeU1r3NYQPalEu1VWvHloNVkbs3UyuPyZy1ep3L8pR5zxJtwuiFNxWUTtOlcEaFLN1doF2/ZnZk3XMhEvYoKEKAp+J/okbuP36v7Mz3a6P8aVyL/y+dcZLdQZY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=LkwWgCSq; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="LkwWgCSq" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0455F1F000E9; Wed, 5 Aug 2026 06:11:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1785910297; bh=o06/6FPH7j0zA4EIe85PZVZwlMghUXEo1x/4oJlkPUw=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=LkwWgCSqVEHenrGLY5DwHpwv7bCvEcjU1bM/SAkxZR2C7FbjCYG3GZB5To0YtXKhJ BROZukET64rl4TaA+ifSfCscJVUF45Sj1Mbg8SEyLyuM5osT/W4PTtOdU+dpW/5eRG lT1en6InMlUBFn/zGgyPhjerWsf2AfB8VVnhSXw4voTEHz6UfS0qFAT9XSyOwjJ8fM f54q8nYfmXaOeDNfFsURdyQ4grrm1xxLOlAzlipOCf89+cNJXPeLxgPi2gG5ZvQVWv qF4AxGW4BsKoX4/f0sTLmGSj0EsjUXEQ/4Y3hV+0ZhQ0+P1Cw/fzmiNjZE2Z54f5q5 k+NL4/dHq1Unw== Message-ID: <17add1ab-4390-4e8c-95ce-b8f0723d4c79@kernel.org> Date: Wed, 5 Aug 2026 08:11:29 +0200 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: [RFC v2 PATCH 0/16] Optimize this_cpu_*() ops for non-x86 (ARM64 for this series) To: "Christoph Lameter (Ampere)" Cc: Yang Shi , "Lorenzo Stoakes (ARM)" , Linus Torvalds , Mark Rutland , 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 References: <20260715180455.515692-1-yang@os.amperecomputing.com> <0344c559-1959-4531-9265-d5a5180eb7cd@arm.com> <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> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit On 8/5/26 00:35, 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? That's best asked in reply to Mark's patch set I think. -- Cheers, David