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
Subject: Re: [dpdk-dev] [PATCH v7 1/3] ethdev: new API to free consumed buffers in Tx ring
Date: Fri, 24 Mar 2017 14:30:57 +0100 [thread overview]
Message-ID: <20170324143057.75e2143f@platinum> (raw)
In-Reply-To: <CAKLkqD4t3R4w4MC+rw8TDraDC=gP8uf-gu3jmch-6aCbw1nooA@mail.gmail.com>
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
next prev parent reply other threads:[~2017-03-24 13:38 UTC|newest]
Thread overview: 54+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-01-20 16:01 [dpdk-dev] [PATCH v3 0/3] " Billy McFall
2017-01-20 16:01 ` [dpdk-dev] [PATCH v3 1/3] ethdev: " Billy McFall
2017-01-20 16:01 ` [dpdk-dev] [PATCH v3 2/3] net/e1000: e1000 igb support to free consumed buffers Billy McFall
2017-01-22 3:47 ` Lu, Wenzhuo
2017-01-23 13:49 ` Billy McFall
2017-01-24 0:42 ` Lu, Wenzhuo
2017-01-20 16:01 ` [dpdk-dev] [PATCH v3 3/3] net/vhost: vHost " Billy McFall
2017-01-23 15:25 ` [dpdk-dev] [PATCH v3 0/3] new API to free consumed buffers in Tx ring Thomas Monjalon
2017-01-23 21:13 ` [dpdk-dev] [PATCH v4 " Billy McFall
2017-01-23 21:13 ` [dpdk-dev] [PATCH v4 1/3] ethdev: " Billy McFall
2017-01-23 21:13 ` [dpdk-dev] [PATCH v4 2/3] net/e1000: e1000 igb support to free consumed buffers Billy McFall
2017-01-23 21:13 ` [dpdk-dev] [PATCH v4 3/3] net/vhost: vHost " Billy McFall
2017-01-27 18:37 ` [dpdk-dev] [PATCH v5 0/3] new API to free consumed buffers in Tx ring Billy McFall
2017-01-27 18:37 ` [dpdk-dev] [PATCH v5 1/3] ethdev: " Billy McFall
2017-02-27 13:48 ` Thomas Monjalon
2017-03-07 14:29 ` Billy McFall
2017-03-07 16:03 ` Thomas Monjalon
2017-03-09 15:49 ` Billy McFall
2017-03-09 17:11 ` Thomas Monjalon
2017-03-07 16:35 ` Mcnamara, John
2017-03-07 16:42 ` Mcnamara, John
2017-01-27 18:37 ` [dpdk-dev] [PATCH v5 2/3] net/e1000: e1000 igb support to free consumed buffers Billy McFall
2017-02-27 13:49 ` Thomas Monjalon
2017-02-28 1:07 ` Lu, Wenzhuo
2017-01-27 18:38 ` [dpdk-dev] [PATCH v5 3/3] net/vhost: vHost " Billy McFall
2017-02-27 13:50 ` Thomas Monjalon
2017-02-28 6:41 ` Yuanhan Liu
2017-03-01 10:15 ` Maxime Coquelin
2017-03-07 21:59 ` [dpdk-dev] [PATCH v5 0/3] new API to free consumed buffers in Tx ring Thomas Monjalon
2017-03-09 20:51 ` [dpdk-dev] [PATCH v6 " Billy McFall
2017-03-09 20:51 ` [dpdk-dev] [PATCH v6 1/3] ethdev: " Billy McFall
2017-03-15 10:29 ` Olivier Matz
2017-03-15 15:01 ` Billy McFall
2017-03-15 10:30 ` Thomas Monjalon
2017-03-09 20:51 ` [dpdk-dev] [PATCH v6 2/3] net/e1000: e1000 igb support to free consumed buffers Billy McFall
2017-03-13 3:17 ` Lu, Wenzhuo
2017-03-09 20:51 ` [dpdk-dev] [PATCH v6 3/3] net/vhost: vHost " Billy McFall
2017-03-15 10:27 ` Thomas Monjalon
2017-03-15 18:02 ` [dpdk-dev] [PATCH v7 0/3] new API to free consumed buffers in Tx ring Billy McFall
2017-03-15 18:02 ` [dpdk-dev] [PATCH v7 1/3] ethdev: " Billy McFall
2017-03-23 10:37 ` Olivier MATZ
2017-03-23 13:32 ` Billy McFall
2017-03-24 12:46 ` Olivier Matz
2017-03-24 13:18 ` Billy McFall
2017-03-24 13:30 ` Olivier Matz [this message]
2017-03-15 18:02 ` [dpdk-dev] [PATCH v7 2/3] net/e1000: e1000 igb support to free consumed buffers Billy McFall
2017-03-15 18:02 ` [dpdk-dev] [PATCH v7 3/3] net/vhost: vHost " Billy McFall
2017-03-15 20:25 ` [dpdk-dev] [PATCH v7 0/3] new API to free consumed buffers in Tx ring Wiles, Keith
2017-03-24 18:55 ` [dpdk-dev] [PATCH v8 " Billy McFall
2017-03-24 18:55 ` [dpdk-dev] [PATCH v8 1/3] ethdev: " Billy McFall
2017-03-24 18:55 ` [dpdk-dev] [PATCH v8 2/3] net/e1000: e1000 igb support to free consumed buffers Billy McFall
2017-03-24 18:55 ` [dpdk-dev] [PATCH v8 3/3] net/vhost: vHost " Billy McFall
2017-03-27 15:20 ` [dpdk-dev] [PATCH v8 0/3] new API to free consumed buffers in Tx ring Thomas Monjalon
2017-04-19 16:25 ` Ferruh Yigit
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