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* [dpdk-users] rte_eth_from_rings: how to free descriptors
@ 2020-02-04  7:53 Volkan Atlı
  0 siblings, 0 replies; 2+ messages in thread
From: Volkan Atlı @ 2020-02-04  7:53 UTC (permalink / raw)
  To: users; +Cc: avatli

Hi

I'm trying to use rte_eth_from_rings() to allow data exchange between cores using rings to be done in the same way as sending or receiving packets from an Ethernet device.  However, I don't understand exactly how rte_mbuf descriptors are cleaned.

For example, for a forwarding application, I don't need to free an rte_mbuf when I use rte_eth_rx_burst() and rte_eth_tx_burst() on the real Ethernet device. Because the rte_eth_tx_burst() function picks up the next available descriptor in the transmit ring and frees the network buffer previously sent with that descriptor. As a result, I do not need to free rte_mbuf descriptor since it will be freed in rte_eth_tx_burst().  Please correct me if I'm wrong.

Does the same behavior apply to rte_eth_from_rings() model? If so, I have to copy the rte_mbuf from pseudo-Ethernet port (created by rte_eth_from_rings) to send to a real Ethernet port, otherwise it will be freed twice (in the 2th and 4rd below). Is there any other way than copy? Please correct me if it is wrong.

app_1
1) allocate rte_mbuf
2) sent the rte_mbuf to pseudo-Ethernet using rte_eth_tx_burst()

app_2
3) pseudo-Ethernet rte_eth_rx_burst()
4) real-Ethernet rte_eth_tx_burst()

Best regards...

Volkan



^ permalink raw reply	[flat|nested] 2+ messages in thread

* [dpdk-users] rte_eth_from_rings: how to free descriptors
@ 2020-02-04 11:22 avatli
  0 siblings, 0 replies; 2+ messages in thread
From: avatli @ 2020-02-04 11:22 UTC (permalink / raw)
  To: users; +Cc: volkan.atli


Hi

I'm trying to use rte_eth_from_rings() to allow data exchange between  
cores using rings to be done in the same way as sending or receiving  
packets from an Ethernet device.  However, I don't understand exactly  
how rte_mbuf descriptors are cleaned.

For example, for a forwarding application, I don't need to free an  
rte_mbuf when I use rte_eth_rx_burst() and rte_eth_tx_burst() on the  
real Ethernet device. Because the rte_eth_tx_burst() function picks up  
the next available descriptor in the transmit ring and frees the  
network buffer previously sent with that descriptor. As a result, I do  
not need to free rte_mbuf descriptor since it will be freed in  
rte_eth_tx_burst().  Please correct me if I'm wrong.

Does the same behavior apply to rte_eth_from_rings() model? If so, I  
have to copy the rte_mbuf from pseudo-Ethernet port (created by  
rte_eth_from_rings) to send to a real Ethernet port, otherwise it will  
be freed twice (in the 2th and 4rd below). Is there any other way than  
copy? Please correct me if it is wrong.

app_1
1) allocate rte_mbuf
2) sent the rte_mbuf to pseudo-Ethernet using rte_eth_tx_burst()

app_2
3) pseudo-Ethernet rte_eth_rx_burst()
4) real-Ethernet rte_eth_tx_burst()

Best regards...

Volkan


^ permalink raw reply	[flat|nested] 2+ messages in thread

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2020-02-04  7:53 [dpdk-users] rte_eth_from_rings: how to free descriptors Volkan Atlı
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