From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932503AbcKGPzI (ORCPT ); Mon, 7 Nov 2016 10:55:08 -0500 Received: from shards.monkeyblade.net ([184.105.139.130]:34174 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932199AbcKGPzF (ORCPT ); Mon, 7 Nov 2016 10:55:05 -0500 Date: Mon, 07 Nov 2016 10:55:00 -0500 (EST) Message-Id: <20161107.105500.43380129278294700.davem@davemloft.net> To: madalin.bucur@nxp.com Cc: netdev@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, oss@buserror.net, ppc@mindchasers.com, joe@perches.com, pebolle@tiscali.nl, joakim.tjernlund@transmode.se Subject: Re: [PATCH net-next v6 02/10] dpaa_eth: add support for DPAA Ethernet From: David Miller In-Reply-To: References: <1478117854-8952-3-git-send-email-madalin.bucur@nxp.com> <20161103.155816.642712588084106823.davem@davemloft.net> X-Mailer: Mew version 6.7 on Emacs 24.5 / Mule 6.0 (HANACHIRUSATO) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Mon, 07 Nov 2016 06:55:30 -0800 (PST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Madalin-Cristian Bucur Date: Mon, 7 Nov 2016 15:43:26 +0000 >> From: David Miller [mailto:davem@davemloft.net] >> Sent: Thursday, November 03, 2016 9:58 PM >> >> Why? By clearing this, you disallow an important fundamental way to do >> performane testing, via pktgen. > > The Tx path in DPAA requires one to insert a back-pointer to the skb into > the Tx buffer. On the Tx confirmation path the back-pointer in the buffer > is used to release the skb. If Tx buffer is shared we'd alter the back-pointer > and leak/double free skbs. See also Then have your software state store an array of SKB pointers, one for each TX ring entry, just like every other driver does.