On 28/05/15 16:00, Ola Liljedahl wrote:
I disprove of this solution. TX completion processing (cleaning TX
descriptor rings after transmission complete) is an implementation
(hardware) aspect and should be hidden from the application.
Unfortunately you can't, if you want your pktio application work with
poll mode drivers. In that case TX completion interrupt (can be)
disabled and the application has to control that as well. In case of
DPDK you just call the send function (with 0 packets, if you don't have
anything to send at the time)
There isn't
any corresponding call that refills the RX descriptor rings with fresh
buffers.
You can do that in the receive function, I think that's how the drivers
are doing it generally.
The completion processing can be performed from any ODP call, not
necessary odp_pktio_send().
I think "any" is not specific enough. Which one?
Can you provide a vague draft how would you fix the l2fwd example below?
-- Ola
On 28 May 2015 at 16:38, Zoltan Kiss <[email protected]
<mailto:[email protected]>> wrote:
A pktio interface can be used with poll mode drivers, where TX
completion often
has to be done manually. This turned up as a problem with ODP-DPDK and
odp_l2fwd:
while (!exit_threads) {
pkts = odp_pktio_recv(pktio_src,...);
if (pkts <= 0)
continue;
...
if (pkts_ok > 0)
odp_pktio_send(pktio_dst, pkt_tbl, pkts_ok);
...
}
In this example we never call odp_pktio_send() on pktio_dst if there
wasn't
any new packets received on pktio_src. DPDK needs manual TX
completion. The
above example should have an odp_pktio_send_completion(pktio_dst)
right at the
beginning of the loop.
Signed-off-by: Zoltan Kiss <[email protected]
<mailto:[email protected]>>
---
include/odp/api/packet_io.h | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/include/odp/api/packet_io.h b/include/odp/api/packet_io.h
index b97b2b8..3a4054c 100644
--- a/include/odp/api/packet_io.h
+++ b/include/odp/api/packet_io.h
@@ -119,6 +119,22 @@ int odp_pktio_recv(odp_pktio_t pktio,
odp_packet_t pkt_table[], int len);
int odp_pktio_send(odp_pktio_t pktio, odp_packet_t pkt_table[],
int len);
/**
+ * Release sent packets
+ *
+ * This function should be called after sending on a pktio. If the
platform
+ * doesn't implement send completion in other ways, this function
should call
+ * odp_packet_free() on packets where transmission is already
completed. It can
+ * be a no-op if the platform guarantees that the packets will be
released upon
+ * completion, but the application must call it periodically after
send to make
+ * sure packets are released.
+ *
+ * @param pktio ODP packet IO handle
+ *
+ * @retval <0 on failure
+ */
+int odp_pktio_send_complete(odp_pktio_t pktio);
+
+/**
* Set the default input queue to be associated with a pktio handle
*
* @param pktio ODP packet IO handle
--
1.9.1
_______________________________________________
lng-odp mailing list
[email protected] <mailto:[email protected]>
https://lists.linaro.org/mailman/listinfo/lng-odp
_______________________________________________
lng-odp mailing list
[email protected]
https://lists.linaro.org/mailman/listinfo/lng-odp
