From mboxrd@z Thu Jan 1 00:00:00 1970 From: Oliver Hartkopp Subject: Re: C_CAN: can frame drops Date: Thu, 31 Jul 2014 16:11:21 +0200 Message-ID: <53DA4E89.1080206@hartkopp.net> References: <53D204A4.1060502@pengutronix.de> <53D2126C.40600@pengutronix.de> <53D214E2.7020205@pengutronix.de> <53D219E8.5060307@pengutronix.de> <53D234D9.2010602@hartkopp.net> ,<53D91AB5.5060507@hartkopp.net> <53DA39CF.2070303@pengutronix.de> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: Received: from mo4-p00-ob.smtp.rzone.de ([81.169.146.218]:12783 "EHLO mo4-p00-ob.smtp.rzone.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750768AbaGaOL3 (ORCPT ); Thu, 31 Jul 2014 10:11:29 -0400 In-Reply-To: <53DA39CF.2070303@pengutronix.de> Sender: linux-can-owner@vger.kernel.org List-ID: To: Marc Kleine-Budde , Ssagarr Patil , Prabhakar Lad Cc: "linux-can@vger.kernel.org" On 31.07.2014 14:42, Marc Kleine-Budde wrote: > On 07/31/2014 02:41 PM, Ssagarr Patil wrote: >>> But so far there was no feedback from Sagar, if it was at least helpful. >>> >> Yes it was beneficial I used MSG_WAITALL flag for recvmmsg() so that >> it waits for n frames and there is no memory wastage. >> This is probably not usable for candump, which has to provide the displayed CAN frames pretty fast. I think there's some timeout mechanism too, to stop the infinitive waiting for n frames. >> Also is it possible to configure qdiscs for improving the performance ? > > AFAIK qdiscs are only used in the tx path. Yep! See: http://rtime.felk.cvut.cz/can/socketcan-qdisc-final.pdf Regards, Oliver