From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marc Kleine-Budde Subject: Re: [PATCH RFC] can: replace timestamp as unique skb attribute Date: Wed, 1 Jul 2015 10:01:18 +0200 Message-ID: <55939E4E.8050908@pengutronix.de> References: <1435312699-25999-1-git-send-email-socketcan@hartkopp.net> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="hngQMGBIx21ugeUbDkoQoxVTHKqoV9eRm" Return-path: Received: from metis.ext.pengutronix.de ([92.198.50.35]:36458 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752918AbbGAIBj (ORCPT ); Wed, 1 Jul 2015 04:01:39 -0400 In-Reply-To: <1435312699-25999-1-git-send-email-socketcan@hartkopp.net> Sender: linux-can-owner@vger.kernel.org List-ID: To: Oliver Hartkopp , linux-can@vger.kernel.org Cc: manfred.schlaegl@gmx.at, tom_usenet@optusnet.com.au, s.grosjean@peak-system.com This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --hngQMGBIx21ugeUbDkoQoxVTHKqoV9eRm Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On 06/26/2015 11:58 AM, Oliver Hartkopp wrote: > Commit 514ac99c64b "can: fix multiple delivery of a single CAN frame fo= r > overlapping CAN filters" requires the skb->tstamp to be set to check fo= r > identical CAN skbs. >=20 > Without timestamping to be required by user space applications this tim= estamp > was not generated which lead to commit 36c01245eb8 "can: fix loss of CA= N > frames in raw_rcv" - which forces the timestamp to be set in all CAN re= lated > skbuffs by introducing several __net_timestamp() calls. >=20 > This forces e.g. out of tree drivers to add __net_timestamp() after skb= uff > creation to prevent the frame loss fixed in mainline Linux. >=20 > This patch removes the timestamp dependency and uses an atomic counter = to > create an unique identifier together with the skbuff pointer. >=20 > Btw. the new skbcnt element introduced in struct can_skb_priv has to be= > initialized with zero in out-of-tree drivers too. =2E..but only if they don't use alloc_can{,fd}_skb().=09 Looks much better than the timestamp approach. I'll apply it to can/master if there aren't any objections. What about stable? Marc --=20 Pengutronix e.K. | Marc Kleine-Budde | Industrial Linux Solutions | Phone: +49-231-2826-924 | Vertretung West/Dortmund | Fax: +49-5121-206917-5555 | Amtsgericht Hildesheim, HRA 2686 | http://www.pengutronix.de | --hngQMGBIx21ugeUbDkoQoxVTHKqoV9eRm Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQEcBAEBCgAGBQJVk55OAAoJEP5prqPJtc/HtfsH/3VGW1TkKnpBLY5XS9cqJn9p gWSQGA+7hXMpZ6Alb2OiBstAlYMV3DqbcNKmKAIGhp0Bgkma05rYyp2p+b7pA+rF oVO4O7QRPvsoY1ERr/MWMv3WI3J9bCIzXGvflwSbtMAqcn+mzvap54xYO5HrYFG2 izK3ohPqkxdxulB0RjXzS18hT/W0Q9BYW1J1GoRCueDtuHNbKKj39JqNur2gZ0AC BOmPbQY7QrppXyYsa2oUOVuRbH1DM9YZmFcYD4siEahlgiW3+skKi7ONhNXrr1L/ Uw8beDfR2poqwGoDi+J+Id+V/A+uvNu/Q1IJpaT2cPRnHEg1nRmmdYrJcTG0sFI= =Eap3 -----END PGP SIGNATURE----- --hngQMGBIx21ugeUbDkoQoxVTHKqoV9eRm--