From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964862AbWAGIDA (ORCPT ); Sat, 7 Jan 2006 03:03:00 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964865AbWAGIDA (ORCPT ); Sat, 7 Jan 2006 03:03:00 -0500 Received: from mx1.redhat.com ([66.187.233.31]:44780 "EHLO mx1.redhat.com") by vger.kernel.org with ESMTP id S964862AbWAGIC7 (ORCPT ); Sat, 7 Jan 2006 03:02:59 -0500 Message-ID: <43BF7598.1070702@redhat.com> Date: Sat, 07 Jan 2006 00:02:32 -0800 From: Ulrich Drepper Organization: Red Hat, Inc. User-Agent: Mail/News 1.5 (X11/20060103) MIME-Version: 1.0 To: Andrew Morton , linux-kernel@vger.kernel.org Subject: Re: [PATCH 0/3] updated *at function patch References: <200601061904.k06J4T3r027891@devserv.devel.redhat.com> <20060106234738.2445520e.akpm@osdl.org> In-Reply-To: <20060106234738.2445520e.akpm@osdl.org> X-Enigmail-Version: 0.93.1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig93017B58023423B08C8AA537" 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) --------------enig93017B58023423B08C8AA537 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Andrew Morton wrote: > We don't have changelogs for these patches. Apart from the usual > what-it-does and how-it-does it I'd really like to be reminded of the > "why". Adding a bunch of stuff to the core kernel codepaths needs to h= ave > a good reason and I've forgotten your rationale. This is the intro from the first set of patches I sent (I adjusted it for the additional syscalls): =3D=3D=3D=3D Here is a series of patches which introduce in total 13 new system calls which take a file descriptor/filename pair instead of a single file name. These functions, openat etc, have been discussed on numerous occasions. They are needed to implement race-free filesystem traversal, they are necessary to implement a virtual per-thread current working directory (think multi-threaded backup software), etc. We have in glibc today implementations of the interfaces which use the /proc/self/fd magic. But this code is rather expensive. Here are some results (similar to what Jim Meyering posted before). The test creates a deep directory hierarchy on a tmpfs filesystem. Then rm -fr is used to remove all directories. Without syscall support I get this: real 0m31.921s user 0m0.688s sys 0m31.234s With syscall support the results are much better: real 0m20.699s user 0m0.536s sys 0m20.149s =3D=3D=3D=3D=3D > We'll need Signed-off_by:'s for all these patches. I'm not sure how you want to handle this. I don't particularly want to resent all of them just for this purpose. [PATCH 1/3] updated *at function patch Signed-off-by: Ulrich Drepper [PATCH 2/3] updated *at function patch Signed-off-by: Ulrich Drepper [PATCH 3/3] updated *at function patch Signed-off-by: Ulrich Drepper --=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 --------------enig93017B58023423B08C8AA537 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 iD8DBQFDv3WY2ijCOnn/RHQRAi1iAJ0UtCK4HCYRGjRc7Xb59CDZbze8pQCbBsnc /4U/4VYM3dPEuZQM71xdjAc= =IJyK -----END PGP SIGNATURE----- --------------enig93017B58023423B08C8AA537--