05/01/2024 10:57, Jerin Jacob: > On Thu, Jan 4, 2024 at 11:59 PM Thomas Monjalon <tho...@monjalon.net> wrote: > > > > 04/01/2024 15:21, Konstantin Ananyev: > > > > > > > > > Introduce a new API to retrieve the number of available free > > > > > > descriptors > > > > > > in a Tx queue. Applications can leverage this API in the fast path > > > > > > to > > > > > > inspect the Tx queue occupancy and take appropriate actions based > > > > > > on the > > > > > > available free descriptors. > > > > > > > > > > > > A notable use case could be implementing Random Early Discard (RED) > > > > > > in software based on Tx queue occupancy. > > > > > > > > > > > > Signed-off-by: Jerin Jacob <jer...@marvell.com> > > > > > > > > > > I think having an API to get the number of free descriptors per queue > > > > > is a good idea. Why have it only for TX queues and not for RX > > > > queues as well? > > > > > > > > I see no harm in adding for Rx as well. I think, it is better to have > > > > separate API for each instead of adding argument as it is fast path > > > > API. > > > > If so, we could add a new API when there is any PMD implementation or > > > > need for this. > > > > > > I think for RX we already have similar one: > > > /** @internal Get number of used descriptors on a receive queue. */ > > > typedef uint32_t (*eth_rx_queue_count_t)(void *rxq); > > > > rte_eth_rx_queue_count() gives the number of Rx used descriptors > > rte_eth_rx_descriptor_status() gives the status of one Rx descriptor > > rte_eth_tx_descriptor_status() gives the status of one Tx descriptor > > > > This patch is adding a function to get Tx available descriptors, > > rte_eth_tx_queue_free_desc_get(). > > I can see a symmetry with rte_eth_rx_queue_count(). > > For consistency I would rename it to rte_eth_tx_queue_free_count(). > > > > Should we add rte_eth_tx_queue_count() and rte_eth_rx_queue_free_count()? > > IMO, rte_eth_rx_queue_free_count() is enough as > used count = total desc number(configured via nb_tx_desc with > rte_eth_tx_queue_setup()) - free count
I'm fine with that.
