From mboxrd@z Thu Jan 1 00:00:00 1970 From: jamal Subject: Re: pktgen question Date: Sun, 23 Sep 2007 14:18:47 -0400 Message-ID: <1190571527.4256.78.camel@localhost> References: <46F6905C.6030309@opengridcomputing.com> <20070923172803.GA11997@2ka.mipt.ru> <46F6A887.1030301@opengridcomputing.com> Reply-To: hadi@cyberus.ca Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: Evgeniy Polyakov , netdev@vger.kernel.org, Robert Olsson To: Steve Wise Return-path: Received: from an-out-0708.google.com ([209.85.132.247]:2989 "EHLO an-out-0708.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755024AbXIWSSv (ORCPT ); Sun, 23 Sep 2007 14:18:51 -0400 Received: by an-out-0708.google.com with SMTP id d31so196561and for ; Sun, 23 Sep 2007 11:18:51 -0700 (PDT) In-Reply-To: <46F6A887.1030301@opengridcomputing.com> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Sun, 2007-23-09 at 12:55 -0500, Steve Wise wrote: > Its a hack that breaks cxgb3 because cxgb3 uses the skb->cb area for > each skb passed down. So cxgb3 is at fault then? IE a driver cannot > use the skb->cb field if the users count is > 1? Or maybe a driver can > _never_ use the cb field? any layer can use the cb structure whichever way they wish. There are violations, e.g: the vlan code also uses the cb field to pass vlan details for hardware acceleration. How does pktgen affect it though, clone() will just copy the cb field and pktgen doesnt touch it. In retrospect, pktgen may have to use clone - ccing Robert Olsson. cheers, jamal