From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: <olivier.matz@6wind.com> Received: from mail-wr0-f180.google.com (mail-wr0-f180.google.com [209.85.128.180]) by dpdk.org (Postfix) with ESMTP id 14A6ED1A2 for <dev@dpdk.org>; Fri, 24 Mar 2017 14:38:27 +0100 (CET) Received: by mail-wr0-f180.google.com with SMTP id l43so1931266wre.1 for <dev@dpdk.org>; Fri, 24 Mar 2017 06:38:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=6wind-com.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=vulhPx4L5HyPy6+l9+YYSdwP0/iXYlXCTZen6JPhz84=; b=q4T3r0u5FyDsYWs6LcYFkqCNlPYxvBHOTevBqqCZN0duQVIZ/f65mz7gWmV0+tzdVL qHpWCojOoKOR0g/xSqWEQ6rFt++14u8zM0WehsKXTGpLLaDAUYdVENRF4aIxDi+357v/ jmoCFLl8NLMm7gsHQuwKFGmgJNWcHPdIJ8uGutwGDu7OkOHuv4C2ktvpcnKRjPSRiYun ym28I0nBHs5YffbTldTxm5aHXOEf2vryOGuU66XpyTferzoyPaUsRxkFZiV99USkPfYj CyVNi+A7I5kMxGRyViFPqlBH1YkHeGx6FDtpuhTPlOf9c87Dzi4xBH/oTo6Jk52rnNX7 TcrQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=vulhPx4L5HyPy6+l9+YYSdwP0/iXYlXCTZen6JPhz84=; b=Ogcu884VtfQL2n/Y4lAgGnusVmCTH5PjXtL8hm3G/u4/75rq/P8BL62xrdF7sU0ZIH q26z15qxEQGgFWCnOqJ/Xyd9BIYSVq+Ibhs/XwWqZnuTr4fKh9Q5GeFcyNHjZmBb8Ul9 7sCQiJwPrlws/8ZTPtvE92RYTz9vvEl+rzzmyteaguBkLWFZ4Oaef8X+V1L2d5nF7kj3 nhb4G8whhhPlR3bgApbmVLgreS0Ylp/1SADOUXERzB7SuJLlTsLXRmWQ2jFObb5RLgs1 81wPtzyELXOGd5mIG/+oXUWsdb5AhjDnoGJX92ecAD39b0B8/OrmJN1YRDDfJ4e+s2nH b9xA== X-Gm-Message-State: AFeK/H0HrifdYjl5upFc1sSbn6GpXXZ4enXs9zFMZNP/tjlvakSgGJ46kX/vL3vyhdjshLkD X-Received: by 10.223.176.250 with SMTP id j55mr7521916wra.11.1490362260252; Fri, 24 Mar 2017 06:31:00 -0700 (PDT) Received: from platinum (2a01cb0c03c651000226b0fffeed02fc.ipv6.abo.wanadoo.fr. [2a01:cb0c:3c6:5100:226:b0ff:feed:2fc]) by smtp.gmail.com with ESMTPSA id 11sm2910392wrb.10.2017.03.24.06.30.59 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Fri, 24 Mar 2017 06:31:00 -0700 (PDT) Date: Fri, 24 Mar 2017 14:30:57 +0100 From: Olivier Matz <olivier.matz@6wind.com> To: Billy McFall <bmcfall@redhat.com> Cc: thomas.monjalon@6wind.com, wenzhuo.lu@intel.com, dev@dpdk.org Message-ID: <20170324143057.75e2143f@platinum> In-Reply-To: <CAKLkqD4t3R4w4MC+rw8TDraDC=gP8uf-gu3jmch-6aCbw1nooA@mail.gmail.com> References: <20170309205119.28170-1-bmcfall@redhat.com> <20170315180226.5999-1-bmcfall@redhat.com> <20170315180226.5999-2-bmcfall@redhat.com> <20170323113716.57e27591@glumotte.dev.6wind.com> <CAKLkqD7WffB9t14wQ9vyphGsL2-mpMhNdMa2Ss7aeKyK8odyKg@mail.gmail.com> <20170324134634.3e764423@platinum> <CAKLkqD4t3R4w4MC+rw8TDraDC=gP8uf-gu3jmch-6aCbw1nooA@mail.gmail.com> X-Mailer: Claws Mail 3.14.1 (GTK+ 2.24.31; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Subject: Re: [dpdk-dev] [PATCH v7 1/3] ethdev: new API to free consumed buffers in Tx ring X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions <dev.dpdk.org> List-Unsubscribe: <http://dpdk.org/ml/options/dev>, <mailto:dev-request@dpdk.org?subject=unsubscribe> List-Archive: <http://dpdk.org/ml/archives/dev/> List-Post: <mailto:dev@dpdk.org> List-Help: <mailto:dev-request@dpdk.org?subject=help> List-Subscribe: <http://dpdk.org/ml/listinfo/dev>, <mailto:dev-request@dpdk.org?subject=subscribe> X-List-Received-Date: Fri, 24 Mar 2017 13:38:28 -0000 On Fri, 24 Mar 2017 09:18:54 -0400, Billy McFall <bmcfall@redhat.com> wrote: > On Fri, Mar 24, 2017 at 8:46 AM, Olivier Matz <olivier.matz@6wind.com> > wrote: [...] > > > I read through this patch. This API doesn't indicate if the packet was > > > transmitted or dropped (I think that is what you were asking). This API > > > could be used by the application to determine if the mbuf has been > > > freed, as opposed to polling the rte_mbuf_refcnt_read() for a change > > > in value. Did I miss your point? > > > > Maybe my question was not clear :) > > Let me try to reword it. > > > > For a traffic generator use-case, a dummy algorithm may be: > > > > 1/ send packets in a loop until a condition is met (ex: packet count > > reached) > > 2/ call rte_eth_tx_done_cleanup() > > 3/ read stats for report > > > > I think there is something missing between 1/ and 2/, to ensure that > > all packets that were in the tx queue are processed (either transmitted > > or dropped). If that's not the case, both steps 2/ and 3/ will not > > behave as expected: > > - all mbufs won't be returned to the pool > > - statistics may be wrong > > > > Maybe a simple wait() could do the job. > > Using a combination of rte_eth_tx_done_cleanup() + > > rte_eth_tx_descriptor_status() > > is probably also a solution. > > > > Do you confirm rte_eth_tx_done_cleanup() does not check that? > > > Confirm. rte_eth_tx_done_cleanup() does not check that. In the flooding > case, > the applications is expected to poll rte_eth_tx_done_cleanup() until some > condition > is met, like ref_count of given packet is decremented. So on the packetGen > case, the > application would need to wait some time and/or call > rte_eth_tx_descriptor_status() > as you suggested. > > My original patch returned RTE_DONE (no more packets pending), > RTE_PROCESSING (freed what I could but there are still packets in the queue) > or -ERRNO for error. Then packets freed count was returned via a pointer in > the param list. > That would have solved what you are asking, but that was shot down as being > overkill. > > Should I add another sentence to the packet generator bullet indicating > that it is the > application's job to make sure no more packets are pending? Like: > > In this case, it can call the ``rte_eth_tx_done_cleanup()`` API for each > destination interface it has been using > to request it to release of all its used mbufs. > + It is the application's responsibility to ensure all packets have been > processed by the destination interface. > + Use rte_eth_tx_descriptor_status() to obtain the status of the transmit > queue, Thanks for the clarification. Not sure the sentence is required, since rte_eth_tx_descriptor_status() is not included yet. Regards, Olivier