在 2020/4/27 21:27, Ferruh Yigit 写道:
On 4/27/2020 1:49 PM, Andrew Rybchenko wrote:
On 4/27/20 3:34 PM, Lijun Ou wrote:
When rte api checks the Rx RSS distribution is enable but the RSS
hash is disabled, it will return an error.
Signed-off-by: Lijun Ou <ouli...@huawei.com>
---
lib/librte_ethdev/rte_ethdev.c | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/lib/librte_ethdev/rte_ethdev.c b/lib/librte_ethdev/rte_ethdev.c
index 0854ef8..07734c4 100644
--- a/lib/librte_ethdev/rte_ethdev.c
+++ b/lib/librte_ethdev/rte_ethdev.c
@@ -1411,6 +1411,17 @@ rte_eth_dev_configure(uint16_t port_id, uint16_t
nb_rx_q, uint16_t nb_tx_q,
goto rollback;
}
+ /* Check if Rx RSS distribution is enable but RSS hash is disabled. */
+ if (((dev_conf->rxmode.mq_mode & ETH_MQ_RX_RSS_FLAG) != 0) &&
+ !(dev_conf->rxmode.offloads & DEV_RX_OFFLOAD_RSS_HASH)) {
+ RTE_ETHDEV_LOG(ERR,
+ "Ethdev port_id=%u config valid Rx mq_mode with RSS but %s
offload is no-requested\n",
+ port_id,
+ rte_eth_dev_rx_offload_name(DEV_RX_OFFLOAD_RSS_HASH));
+ ret = -EINVAL;
+ goto rollback;
+ }
+
/*
* Setup new number of RX/TX queues and reconfigure device.
*/
NACK. It is perfectly fine to do distribution, but do not need RSS hash
information.
- ETH_MQ_RX_RSS_FLAG controls RSS hash calculation and distribution
- DEV_RX_OFFLOAD_RSS_HASH controls delivery of the hash value
itself from HW to SW
Hi Lijun,
As Andrew described, now 'DEV_RX_OFFLOAD_RSS_HASH' controls to copy calculated
hash value to 'mbuf::hash::rss' or not. When rss hash copied to mubf,
'PKT_RX_RSS_HASH' flag of 'mbuf::ol_flags' set to notify the application that
hash value is valid. This was a performance optimization.
if the user is not configure the DEV_RX_OFFLOAD_RSS_HASH and the users
add the ETH_MQ_RX_RSS_FLAG， as a result, the hardware has calculated the
hash result and distributed, the mbuf::o1_flags have set the
PKT_RX_RSS_HASH and the mbuf::hash::rss have set the hash result. What
are the advantage of this configuration with DEV_RX_OFFLOAD_RSS_HASH?
Can I understand it this way, If the user does not apply this rss hash,
does it mean that rss cannot be used to improve performance, even if the
hardware has calculated the rss hash result?
We know above because we were involved in development of it, if this is not
clean for third party, can you please amend your patch to clarify above
behavior?
Thanks,
ferruh
.
