From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marc Kleine-Budde Subject: Re: [PATCH v2 1/2] can: Decrease default size of CAN_RAW socket send queue Date: Thu, 23 Jan 2014 22:01:37 +0100 Message-ID: <52E18331.6050607@pengutronix.de> References: <1390379257-9040-1-git-send-email-sojkam1@fel.cvut.cz> <20140123.124108.891860564230946746.davem@davemloft.net> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="FFxeO8rvE9K4FHuflNcJiO3TPnhscLhUd" Cc: linux-can@vger.kernel.org, netdev@vger.kernel.org To: David Miller , sojkam1@fel.cvut.cz Return-path: In-Reply-To: <20140123.124108.891860564230946746.davem@davemloft.net> Sender: linux-can-owner@vger.kernel.org List-Id: netdev.vger.kernel.org This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --FFxeO8rvE9K4FHuflNcJiO3TPnhscLhUd Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On 01/23/2014 09:41 PM, David Miller wrote: > From: Michal Sojka > Date: Wed, 22 Jan 2014 09:27:36 +0100 >=20 >> Since the length of the qdisc queue was set by default to 10 >> packets, this is exactly what was happening. >=20 > This is your bug, set the qdisc limit to something more reasonable. >=20 > Something large enough to absorb the traffic wrt. the speed at which > the CAN device can sink the data. Hmmm, the problem is on i686 I have to increase the txqueuelen to 366 before the socket works as expected (writes are blocking). This means if there are two processes one sending a stream of bulk data and the other one occasionally more important data there will be a lot of frames in front of the important ones. With Michal's patch we can limit the number of frames in flight to a reasonably low amount. > These two patches are something I am not willing to apply to my > tree, this is not how you solve this problem, sorry. 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 | --FFxeO8rvE9K4FHuflNcJiO3TPnhscLhUd 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 Comment: Using GnuPG with Icedove - http://www.enigmail.net/ iEYEARECAAYFAlLhgzEACgkQjTAFq1RaXHPTNgCdE6HgiMs467WA5VKtrKZsUmve VDEAni4N4t2c1CXpNO1HvdQDYNa4dCYV =g1AI -----END PGP SIGNATURE----- --FFxeO8rvE9K4FHuflNcJiO3TPnhscLhUd--