From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964917AbVL1WOq (ORCPT ); Wed, 28 Dec 2005 17:14:46 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964929AbVL1WOq (ORCPT ); Wed, 28 Dec 2005 17:14:46 -0500 Received: from mx1.redhat.com ([66.187.233.31]:56466 "EHLO mx1.redhat.com") by vger.kernel.org with ESMTP id S964917AbVL1WOp (ORCPT ); Wed, 28 Dec 2005 17:14:45 -0500 Message-ID: <43B30E19.6080207@redhat.com> Date: Wed, 28 Dec 2005 14:13:45 -0800 From: Ulrich Drepper Organization: Red Hat, Inc. User-Agent: Mail/News 1.5 (X11/20051129) MIME-Version: 1.0 To: mpm@selenic.com, akpm@osdl.org CC: linux-kernel@vger.kernel.org, linux-tiny@selenic.com Subject: Re: Fwd: [PATCH] Make sysenter support optional References: <20051228212402.GX3356@waste.org> In-Reply-To: X-Enigmail-Version: 0.93.1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enigDF0E749CB13F96DD47197CD1" Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enigDF0E749CB13F96DD47197CD1 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable > This adds configurable sysenter support on x86. This saves about 5k on > small systems. You not only remove the sysenter support but also the vdso. And the later is a very bad idea. It is already today basically impossible to have reliable backtraces without the vdso and the unwind info it contains for signal handlers. And things can only get worse in future. The magic heuristics in the compiler are not reliable. It's simply the wrong face, this in a interface between the kernel and the libc, the compiler should not have such knowledge. The vdso should be mandatory for all configurations. --=20 =E2=9E=A7 Ulrich Drepper =E2=9E=A7 Red Hat, Inc. =E2=9E=A7 444 Castro St = =E2=9E=A7 Mountain View, CA =E2=9D=96 --------------enigDF0E749CB13F96DD47197CD1 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.2 (GNU/Linux) Comment: Using GnuPG with Fedora - http://enigmail.mozdev.org iD8DBQFDsw4Z2ijCOnn/RHQRAmCbAKC+NTcVW1s6Z8QQExQ2EkHc1KGHzgCdHsZj t/QjzlbmYa96H91HzQCEp2c= =oftl -----END PGP SIGNATURE----- --------------enigDF0E749CB13F96DD47197CD1--