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[2604:1380:40f1:3f00::1]) by mx.google.com with ESMTPS id v10-20020a170902b7ca00b001d74670ffbcsi1719073plz.290.2024.02.07.07.19.55 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 07 Feb 2024 07:19:55 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel+bounces-56697-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:40f1:3f00::1 as permitted sender) client-ip=2604:1380:40f1:3f00::1; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=k20201202 header.b=hE3lMhLz; arc=pass (i=1 dkim=pass dkdomain=kernel.org); spf=pass (google.com: domain of linux-kernel+bounces-56697-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:40f1:3f00::1 as permitted sender) smtp.mailfrom="linux-kernel+bounces-56697-linux.lists.archive=gmail.com@vger.kernel.org"; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Received: from smtp.subspace.kernel.org (wormhole.subspace.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sy.mirrors.kernel.org (Postfix) with ESMTPS id 3D537B28B00 for ; Wed, 7 Feb 2024 15:10:41 +0000 (UTC) Received: from localhost.localdomain (localhost.localdomain [127.0.0.1]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 7B9077F7F2; Wed, 7 Feb 2024 15:10:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="hE3lMhLz" 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 7AD5E7F492 for ; Wed, 7 Feb 2024 15:10:30 +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=1707318631; cv=none; b=WyIoa7NGxmNSSID6I/6bqCC2OAtW23X6SLB43VJwbNIYbEOkQwYwIC86J75SLbtQRegVzUIJ0OoEkvKqp1LT2dI/1ElKo6CseXM7ujQFJFkr4bz1tnFliLUxrc0DoD9T/EaB6faT54/CU+KKUDd0UAqo20anfsEj7qToyZHE1Hw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707318631; c=relaxed/simple; bh=z7kDN/9RKM6srpE/iDGZ736vndtbrUwfOgAVPlVsV8c=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=D4IUmlSpvXoO3jJY9DmDPoa+bdS/HDDyL2R/uxKaHiKdxvSlpPVaJtAEDkymjpsSL+jGk7erfhhMTNhBA+UVYbm0lRa5qnQoQPZTlcMTnDfwSqwzm1rj81782JHPL/SgXMAljsDdIgcn0tdUZGtqs4C2ZqMZevqom1pd/Wj3QwQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=hE3lMhLz; arc=none smtp.client-ip=10.30.226.201 Received: by smtp.kernel.org (Postfix) with ESMTPSA id CEAB7C433C7; Wed, 7 Feb 2024 15:10:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1707318630; bh=z7kDN/9RKM6srpE/iDGZ736vndtbrUwfOgAVPlVsV8c=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=hE3lMhLzAQH18yuIFUsYKJa4oavc9S+ZOM7C87o/RkVIWyhbHXOykv11LTlT0ubiE pwfTt7gkZyE7mEjL8PFIPp6AEj0xRRO9eEPMdIGyh4oErPT67Y6gyiC76DwyW8DBcP K865XTkME9n+0BPkOXHxI+XXst2C+b1/5ODZrgEEHAIX19ds+G2AlR9ZSn2KHjaQjT 0UgPqQZEysM0A+U2eaEgtfs1BQ9X53w/Qme9+jzY1vhMX6SikFCfGVk8OsoEhFd2y/ lJXOCbmLtYx8/OddTinzzv4OWRFB84YAbqGztCANDBMHCxMZDOOsLi9z0ZahG4mSS0 SM3h5NsFOmXdg== Date: Wed, 7 Feb 2024 15:10:28 +0000 From: Mark Brown To: Dave Martin Cc: Catalin Marinas , Will Deacon , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] arm64/sve: Document that __SVE_VQ_MAX is much larger than needed Message-ID: References: <20240206-arm64-sve-vl-max-comment-v1-1-dddf16414412@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="6wd8y45bC39+B3ls" Content-Disposition: inline In-Reply-To: X-Cookie: You might have mail. --6wd8y45bC39+B3ls Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Wed, Feb 07, 2024 at 01:39:13PM +0000, Dave Martin wrote: > How about something along the lines of: > /* > * Yes, this is 512 QUADWORDS. > * To help ensure forward portability, this is much larger than the > * current maximum value defined by the SVE architecture. > * While arrays or static allocations can be sized based on this value, > * watch out! It will waste a surprisingly large amount of memory. > * Dynamic sizing based on the actual runtime vector length is likely to > * be preferable for most purposes. > */ That works for me. The cost of initialising can also add up in emulation. --6wd8y45bC39+B3ls Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAABCgAdFiEEreZoqmdXGLWf4p/qJNaLcl1Uh9AFAmXDnWMACgkQJNaLcl1U h9D6Ugf+JL/cppHvNNJuGS1wEso5Ew3SN0U8U6OhO0o5/EchygtGZBzmsIHkBxLG wLq303vk0lALc3LB0j7Q43kaPzFDg/vIUPbCbdfAohqqVt/3+afBRlFAc3eMg8E9 0bSv+tlbM7TQOZaaC6JPI0jDhxhCCCX97dQ3IxqFo5wq4TYdmo9G6I3LCNVaeCuU q78btLKrrXrXkFAcSdWv2FEUiHeuGDkcrjFS9g6H6Gskrmk0aVWciWjTXC3Jcpel PIVNc8sOCdfnc/QgO61YjxopAV84gnDAlcblSEUoRLsCRKY51o0NvPusGCSsOkUd EX30mUNpWRh2Z2cteqzTcGINiQMXEg== =z019 -----END PGP SIGNATURE----- --6wd8y45bC39+B3ls--