On 10/27/2020 10:24 AM, Bruce Richardson wrote:
On Mon, Sep 14, 2020 at 01:05:11PM +0200, Morten Brørup wrote:
Updated description of rte_eth_rx_burst() to reflect what drivers,
when using vector instructions, expect from nb_pkts.
Also discussed on the mailing list here:
http://inbox.dpdk.org/dev/98cbd80474fa8b44bf855df32c47dc35c61...@smartserver.smartshare.dk/
Signed-off-by: Morten Brørup <m...@smartsharesystems.com>
---
lib/librte_ethdev/rte_ethdev.h | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/lib/librte_ethdev/rte_ethdev.h b/lib/librte_ethdev/rte_ethdev.h
index 70295d7ab..41f8ba4ef 100644
--- a/lib/librte_ethdev/rte_ethdev.h
+++ b/lib/librte_ethdev/rte_ethdev.h
@@ -4469,6 +4469,10 @@ int rte_eth_dev_hairpin_capability_get(uint16_t port_id,
* burst-oriented optimizations in both synchronous and asynchronous
* packet processing environments with no overhead in both cases.
*
+ * @note
+ * Some drivers using vector instructions require that *nb_pkts* is
+ * divisible by 4 or 8, depending on the driver implementation.
+ *
* The rte_eth_rx_burst() function does not provide any error
* notification to avoid the corresponding overhead. As a hint, the
* upper-level application might check the status of the device link once
@@ -4485,6 +4489,7 @@ int rte_eth_dev_hairpin_capability_get(uint16_t port_id,
* must be large enough to store *nb_pkts* pointers in it.
* @param nb_pkts
* The maximum number of packets to retrieve.
+ * The value must be divisible by 8 in order to work with any driver.
* @return
* The number of packets actually retrieved, which is the number
* of pointers to *rte_mbuf* structures effectively supplied to the
--
This correctly documents the current situation, so following the discussion
on-list:
Acked-by: Bruce Richardson <bruce.richard...@intel.com>
Applied to dpdk-next-net/main, thanks.
