Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758580AbYCTVWY (ORCPT ); Thu, 20 Mar 2008 17:22:24 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756026AbYCTVWK (ORCPT ); Thu, 20 Mar 2008 17:22:10 -0400 Received: from crystal.sipsolutions.net ([195.210.38.204]:58639 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753399AbYCTVWJ (ORCPT ); Thu, 20 Mar 2008 17:22:09 -0400 Subject: Re: [PATCH/RFC v2] introduce ARCH_CAN_UNALIGNED_ACCESS Kconfig symbol From: Johannes Berg To: David Miller Cc: sam@ravnborg.org, dsd@gentoo.org, linux-kernel@vger.kernel.org, linux-wireless@vger.kernel.org, netdev@vger.kernel.org In-Reply-To: <20080320.141307.173590705.davem@davemloft.net> References: <1206023695.16475.137.camel@johannes.berg> <20080320181310.GA17884@uranus.ravnborg.org> <1206038373.16475.150.camel@johannes.berg> <20080320.141307.173590705.davem@davemloft.net> Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-U9d2Ty1Jta9zyVzH3MEN" Date: Thu, 20 Mar 2008 22:21:46 +0100 Message-Id: <1206048106.16475.161.camel@johannes.berg> Mime-Version: 1.0 X-Mailer: Evolution 2.12.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2015 Lines: 52 --=-U9d2Ty1Jta9zyVzH3MEN Content-Type: text/plain Content-Transfer-Encoding: quoted-printable > I think you're semantically testing the wrong thing. >=20 > It's not if unaligned accesses are supported, it's if they are > efficient enough or not. >=20 > For example, sparc64 fully handles unaligned accesses but taking the > trap to fix it up is slow. So sparc64 "can" handle unaligned > accesses, but whether we want to set this symbol or not is another > matter. Yeah, good point. Should I rename it to HAVE_EFFICIENT_UNALIGNED_ACCESS or similar? Or have it defined as some sort of number so you can make actually make tradeoffs? Like Dave Woodhouse suggested at some point to have get_unaligned() take an argument that indicates the probability... johannes --=-U9d2Ty1Jta9zyVzH3MEN Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Comment: Johannes Berg (powerbook) iQIVAwUAR+LVaaVg1VMiehFYAQKGEQ//Y7tlbOZ+5VeIOIzFnf+/JvXG5K9e+xRc SeHqW1/P4PBJErnpiu4x7Kskdxnth5prPpNnq6NKq0BwDGbwoKvNmJXDaHHFFsNI tXRkf3eqIcPPDZqkp1COOudY0xXLYxFmt1UR8kPBgpR37MDGg3mZH5/45IotozAh bAOAnFFKXrzk0yYLI7uHEWPV1whAjxKt4kAaTCFzG0r981uz7/EjitNHzdEg0IVe nozFGn1+M7yw0WCaaxEZMzREDUjgmRUE8prRa6eGiqvnRMHhxRds+oauH0Rp0Vhq ZTv2gKJbvF8ylTdHg8JEtRHB6eJhQapf182uyFXOmcgySze1E4rSZ0v4S1+jqGyE AuXQ0phQziwPCja846vwW8hBHEEeFPVOcQEgDuMtzDZjytuILeHqwvfPvZbOEpp+ 5G0FP83RAztR1zE8LDM5WkUWd7mmftgPQgsNMfNhWyHGD/BJ1rv3/Z05B/3kYL0A e9QgNNh3MBvjJte7aFu+PjYpGvF9s9xguOOzmCRtAc6j6IQepQ+Ya87fMi5zRbQn y+k5iJg/e806U3GY2KtFaO+EPjpFUteH9x47hv+T1gl4SCws3W15Vu5zxklBfSUP +nBT2H+NUWAvPNgy9FvN8dmxLBnnmrX6YAZ1piV8N/OyUpQpnoVXCmxlljeGbE9H mza/0C9i4YQ= =zg7i -----END PGP SIGNATURE----- --=-U9d2Ty1Jta9zyVzH3MEN-- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/