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 CA690329360 for ; Wed, 14 Jan 2026 18:16:54 +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=1768414614; cv=none; b=qXquMQTwiFWQ7qo28PhGMMhJqiu8DKNA0opkOIr6s2Y8JtrvJ2NU1iQN1Rak6oLk6UjYYjHVySULilL2dixfdjFoqr1VdvIfxEy1BUoIZ4xHN/Vb1Mk6BxNez926qr5GMmNRgZShzRysJ0ruVha/cXTNAQjo0jxdbd/JUoVCR5g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768414614; c=relaxed/simple; bh=ItC3CUW/lqRPaei9BlHdRw3NjMxWF+PXVxF/ZxVsNfg=; h=Date:From:To:cc:Subject:In-Reply-To:Message-ID:References: MIME-Version:Content-Type; b=L6ovE5vUkSZRyxd9sI5uCC6e53sIRfVlylmARBtzLtyNL20uf4R9rCgB0kE1/zMqx5oR8LR+dTcPVifttQt3/th5TtkK/mIoYRVBwEtTy+DnQc6W1XyEeVdn1QeHU5OEFyGyl9SBThhZ/Y7Xle5zPwsVur/tD+EfsrrnzLzsVcc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=b3AB6yNX; 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="b3AB6yNX" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BF4D1C19424; Wed, 14 Jan 2026 18:16:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1768414614; bh=ItC3CUW/lqRPaei9BlHdRw3NjMxWF+PXVxF/ZxVsNfg=; h=Date:From:To:cc:Subject:In-Reply-To:References:From; b=b3AB6yNXvjXB7nQXKAx9Ib1euVhc0kZi9bpSVwfa+2ia1zRYkamUkEnl0pDETEOwr 7uoMjvXc9Qv0osKGoRZgbgWgZ5L2z8LY8BhghpMPd/u2mFgXxRIXpG7QEkNQuxcLAm 03rZyXb2rnbB7xp4ocv1RgYC+hP54J/0CTz3EUhz/1E66z9EEvT5S9F70q4/7WWEus YA5kh98n/DW8rSPDzoQOSYdR4hgjUCllSzek9z7OfUJHG+zDtSFTaZdJLzKPpW2YVU VAnhfDt+vHSafIXl4vA0u7qQBGt3KBSZ+J7zbJNph9yoT4Yi82Rse7oXT3vRjKYT7b NrSkxlSN0UqGQ== Date: Wed, 14 Jan 2026 11:16:50 -0700 (MST) From: Paul Walmsley To: Charlie Jenkins cc: Paul Walmsley , Palmer Dabbelt , Alexandre Ghiti , Anup Patel , Atish Patra , Samuel Holland , =?ISO-8859-15?Q?Bj=F6rn_T=F6pel?= , Luke Nelson , Xi Wang , Eric Biggers , Conor Dooley , linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, Charlie Jenkins Subject: Re: [PATCH RFC 00/10] riscv: Add support for rva23 In-Reply-To: <20251210-profiles-v1-0-315a6ff2ca5a@gmail.com> Message-ID: <9325a1ab-62e7-e61f-ab55-cc06b582a23a@kernel.org> References: <20251210-profiles-v1-0-315a6ff2ca5a@gmail.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 Hi Charlie, On Wed, 10 Dec 2025, Charlie Jenkins wrote: > I will be talking about rva23 at Plumbers this year and have this series > as a draft of my ideas. > > rva23 is a RVI profile to group together extensions that are expected to > be found on high-performance systems. > > This series: > 1. Introduces a framework to add extensions to the kernel cflags > 2. Adds a rva23 config option > 3. Optimizes riscv_has_extension_* > > This is based on 6.18 plus > https://lore.kernel.org/linux-riscv/20251020-riscv-altn-helper-wip-v4-0-ef941c87669a@iscas.ac.cn/. > > Signed-off-by: Charlie Jenkins Thanks for sending these. A few suggestions, for when you resend these patches: - Please split the cleanup patches into a separate, predecessor series from the patches that are designed to change the way that extensions are handled. The latter patches will probably take longer to reach consensus around. - Probably best not to characterize the latter set of patches as "RVA23 support" patches, since they won't affect the kernel's ability to support RVA23. These just enable building an RVA23-specific kernel. It's not entirely clear to me that this is a win -- I assume the argument would be that the performance benefit for some systems would justify the additional complexity and the performance reduction for other systems? -- but that's what we'd need to discuss. - Continuing that line of thinking, I think we'd want to see some performance measurements after these patches are applied, on hardware, for both RVA23-specific kernels and non-RVA23-specific kernels, and the latter on both non-RVA23 hardware and RVA23 hardware. thanks, - Paul