From: "Jason A. Donenfeld" Subject: Re: [PATCH net-next v6 19/23] zinc: Curve25519 ARM implementation Date: Fri, 5 Oct 2018 20:40:03 +0200 Message-ID: <20181005184001.GA10106@zx2c4.com> References: <20180925145622.29959-1-Jason@zx2c4.com> <20180925145622.29959-20-Jason@zx2c4.com> <20181005150538.17006.qmail@cr.yp.to> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="C7zPtVaVf+AK4Oqc" To: ard.biesheuvel@linaro.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, linux-crypto@vger.kernel.org, davem@davemloft.net, gregkh@linuxfoundation.org, sneves@dei.uc.pt, luto@kernel.org, jeanphilippe.aumasson@gmail.com, linux@armlinux.org.uk, linux-arm-kernel@lists.infradead.org, peter@cryptojedi.org, djb@cr.yp.to Return-path: Content-Disposition: inline In-Reply-To: <20181005150538.17006.qmail@cr.yp.to> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-crypto.vger.kernel.org --C7zPtVaVf+AK4Oqc Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Hey Dan, On Fri, Oct 05, 2018 at 03:05:38PM -0000, D. J. Bernstein wrote: > Of course, there are other ARM microarchitectures, and there are many > cases where different microarchitectures prefer different optimizations. > The kernel already has boot-time benchmarks for different optimizations > for raid6, and should do the same for crypto code, so that implementors > can focus on each microarchitecture separately rather than living in the > barbaric world of having to choose which CPUs to favor. I've been playing a bit with some code to do this sort of thing, choosing a set of implementations to enable or disable by trying all the combinations, and then calculating a quick median. I don't know if I'll submit that for the initial merge of this patchset -- and in fact all the current implementations I'm proposing are pretty much okay on microarchitectures -- but down the line this could be useful as a mechanism. Jason --C7zPtVaVf+AK4Oqc Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCAAdFiEEq5lC5tSkz8NBJiCnSfxwEqXeA64FAlu3r/8ACgkQSfxwEqXe A64NZRAAxHqb5/Z9ObOwhJ6OLx/HnHRBt35TCF7ZOS6CtnOwHr7KYFeWdny4GUvF saghZ8OkUK9g7DVDzDDFOsTtFAjBqrZiqrL7eQAlNszz8Ru2ijsUUqXrgzC2Ikms FDMCZqkbIwHLon/8UelYHz/MW1MgId+HVMjhNzxleE3fdMhgLwGmRkiUMHmBUMBG Xuvljbqfl2Y0jgytW6Np+GeIMHqbWPQjcbsk3lfIsfwAsMcCeA063nlf6f5uVM8Y l+bDhSm2oB9laOXZJc6fl5e+J1TMIQIlpGldXBhHXZU5JrRWr5XnVIbGQYQ3DXSf 2GVdf+Mo0AgkqoMXqIOd07k65dFXDyui0PG0oypxknKRG1d7+Gke8avIOVME+UrK aWGPA74qubEfVzV492wbKrpYhiaeV+VL7qi/4+FP76pRwUFC2KloAi3NFotFXDCA VFzlECZ8H3Ryla+ZnHA7mAJHsIuBZXYqMQScoHUG1zbSg6a8bjUt1gTdAO/vkVvc WZXpewhL23FLOR0C3/J2dkoRdBh3iKb/xG129w9PoA3/v52cCnKe760ZD7TpwSh2 toG7zwJMssriYB+GTvFV1om6Rli+dAP1o9OvqTW8IUA2r3BYJrmVLtKsSIQ1RDjJ M++c1/sfq3ca2bNkoZjFahmNEwP+dMhCcNGXO9RKpYRHzm1agBo= =yJNa -----END PGP SIGNATURE----- --C7zPtVaVf+AK4Oqc--