Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755910AbYKCV7q (ORCPT ); Mon, 3 Nov 2008 16:59:46 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752985AbYKCV7h (ORCPT ); Mon, 3 Nov 2008 16:59:37 -0500 Received: from fg-out-1718.google.com ([72.14.220.159]:33386 "EHLO fg-out-1718.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752945AbYKCV7g (ORCPT ); Mon, 3 Nov 2008 16:59:36 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:user-agent:mime-version:to:subject :x-enigmail-version:content-type; b=RsvkRGza+YFiU4x15WXuIrW3JkcNoL8F2HKEZJp6BHBEqPxhctG5Ccdn/WHlbBZWlV iftGQEosUHmJMSeECxCZfHLxvaaJCX7HidgRjH9oPHWPVHZigHcTsVRQhNTEcAY5eXd7 EvU6wi20faG23vWmj5/ZDpTuCpKn8MhRjSVSc= Message-ID: <490F73CD.4010705@gmail.com> Date: Mon, 03 Nov 2008 23:57:33 +0200 From: "Eugene V. Lyubimkin" User-Agent: Mozilla-Thunderbird 2.0.0.17 (X11/20081018) MIME-Version: 1.0 To: linux-kernel@vger.kernel.org Subject: mmap: is default non-populating behavior stable? X-Enigmail-Version: 0.95.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enigE277DC70624059272E51407A" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1468 Lines: 45 This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enigE277DC70624059272E51407A Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Hello kernel hackers! The current implementation of mmap() in kernel is very convenient. It allows to mmap(fd) very big amount of memory having small file as back= -end. So one can mmap() 100 MiB on empty file, use first 10 KiB of memory, munm= ap() and have only 10 KiB of file at the end. And while working with memory, file will = automatically be grown by read/write memory requests. Question is: can user-space application rely on this behavior (I failed t= o find any documentation about this)? TIA and please CC me in replies. --=20 Eugene V. Lyubimkin aka JackYF --------------enigE277DC70624059272E51407A Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) iEYEARECAAYFAkkPc88ACgkQchorMMFUmYzb0gCcDhSzz+MbkLKj2imeQS3CZPYg g7IAoK7K4DLf1AkY6WOGE2HnQDl4JSHL =/WW7 -----END PGP SIGNATURE----- --------------enigE277DC70624059272E51407A-- -- 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/