From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wi0-f175.google.com (mail-wi0-f175.google.com [209.85.212.175]) by dpdk.org (Postfix) with ESMTP id 58F6B8032 for ; Thu, 4 Dec 2014 16:48:44 +0100 (CET) Received: by mail-wi0-f175.google.com with SMTP id l15so35263038wiw.14 for ; Thu, 04 Dec 2014 07:48:44 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:organization :user-agent:in-reply-to:references:mime-version :content-transfer-encoding:content-type; bh=hCFgYOvRF7AjC7BNio41emHFazrhkt99N115xuuGPY4=; b=TtyIahBC7E3CsDi7XhbLERklFqYRxl7w46OxVH2RdTdUBQ9A7ZNts+33oeWR7arl2j H4wzYcKtFKkv6RdGqZmevoF3P92iLMfRcb7hIvS1P6e0WSmQjJPsl9fp4uC3v3RiD9tm krCNGJwaaK4+OXimybtCcO4UuORfYzPDYE/Bwn+HHiuBa/261yf22WJFaR+vZlLjXCCn biG/uYMozgKxSK3d855HtSgS5z2Pox07XFsBGMa8vjBH374T0bzuqxZqU8pyqDWdADoW zPUPjVKxov/TSLBUfDL5zlSW33i/pBwwTQz9sZ76PwQerfXrmPeZbanRggtVwn8ysWx6 iIZw== X-Gm-Message-State: ALoCoQlE35SpRa6y+br3TYeCcMSlaXCv5oG1JEg+ybYMTAkSJBCvZMu7rOnohIYbBogq5bO74GwC X-Received: by 10.180.73.143 with SMTP id l15mr108835921wiv.24.1417708124207; Thu, 04 Dec 2014 07:48:44 -0800 (PST) Received: from xps13.localnet (136-92-190-109.dsl.ovh.fr. [109.190.92.136]) by mx.google.com with ESMTPSA id p15sm23626627wjr.18.2014.12.04.07.48.42 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 04 Dec 2014 07:48:43 -0800 (PST) From: Thomas Monjalon To: "Ananyev, Konstantin" Date: Thu, 04 Dec 2014 16:48:19 +0100 Message-ID: <4349408.QROSJAq1DS@xps13> Organization: 6WIND User-Agent: KMail/4.14.3 (Linux/3.17.4-1-ARCH; KDE/4.14.3; x86_64; ; ) In-Reply-To: <2601191342CEEE43887BDE71AB977258213BCA80@IRSMSX105.ger.corp.intel.com> References: <1417703181-23093-1-git-send-email-jean-mickael.guerin@6wind.com> <20141204151500.GC9300@bricha3-MOBL3> <2601191342CEEE43887BDE71AB977258213BCA80@IRSMSX105.ger.corp.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Cc: dev@dpdk.org Subject: Re: [dpdk-dev] [PATCH 2/2] ixgbe: don't override mbuf buffer length X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 04 Dec 2014 15:48:44 -0000 2014-12-04 15:29, Ananyev, Konstantin: > From: Richardson, Bruce > > On Thu, Dec 04, 2014 at 02:50:11PM +0000, Ananyev, Konstantin wrote: > > > From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Jean-Mickael Guerin > > > > The template mbuf_initializer is hard coded with a buflen which > > > > might have been set differently by the application at the time of > > > > mbuf pool creation. > > > > > > > > Switch to a mbuf allocation, to fetch the correct default values. > > > > There is no performance impact because this is not a data-plane API. > > > > > > > > Signed-off-by: Jean-Mickael Guerin > > > > Acked-by: David Marchand > > > > Fixes: 0ff3324da2 ("ixgbe: rework vector pmd following mbuf changes") > > > > --- > > > > lib/librte_pmd_ixgbe/ixgbe_rxtx_vec.c | 19 ++++++++++++------- > > > > 1 file changed, 12 insertions(+), 7 deletions(-) > > > > > > > > diff --git a/lib/librte_pmd_ixgbe/ixgbe_rxtx_vec.c b/lib/librte_pmd_ixgbe/ixgbe_rxtx_vec.c > > > > index c1b5a78..f7b02f5 100644 > > > > --- a/lib/librte_pmd_ixgbe/ixgbe_rxtx_vec.c > > > > +++ b/lib/librte_pmd_ixgbe/ixgbe_rxtx_vec.c > > > > @@ -732,17 +732,22 @@ static struct ixgbe_txq_ops vec_txq_ops = { > > > > int > > > > ixgbe_rxq_vec_setup(struct igb_rx_queue *rxq) > > > > { > > > > - struct rte_mbuf mb_def = { .buf_addr = 0 }; /* zeroed mbuf */ > > > > + struct rte_mbuf *mb_def; > > > > > > > > - mb_def.nb_segs = 1; > > > > - mb_def.data_off = RTE_PKTMBUF_HEADROOM; > > > > - mb_def.buf_len = rxq->mb_pool->elt_size - sizeof(struct rte_mbuf); > > > > - mb_def.port = rxq->port_id; > > > > - rte_mbuf_refcnt_set(&mb_def, 1); > > > > + mb_def = rte_pktmbuf_alloc(rxq->mb_pool); > > > > > > Could you explain to me, what is an advantage of using dynamic allocation vs local struct here? > > > I don't see any. > > > > It means that we get an mbuf that is initialized as done by the initialization > > function passed to the mempool_create call. The static variable method assumes > > that we configure the mbuf using default setting for buf_len etc. > > I understand that, but why it can't be done in some other way? > Without allocating/freeing? > Let say, at mempool_create() store obj_init() and then add ability to call it again? > Anyway, it doesn't look to me like a critical problem, that requires an urgent patch for 1.8. Konstantin, when a bug is seen, it must be fixed ASAP. -- Thomas