On Sun, Jun 08, 2025 at 11:32:19AM +0000, Soumyadeep Hore wrote:
> Adding eth_ice_read_clock() feature to get current time
> for scheduling Packets based on Tx time.
>
> Signed-off-by: Soumyadeep Hore <soumyadeep.h...@intel.com>
> ---
> drivers/net/intel/ice/ice_ethdev.c | 13 +++++++++++++
> 1 file changed, 13 insertions(+)
>
> diff --git a/drivers/net/intel/ice/ice_ethdev.c
> b/drivers/net/intel/ice/ice_ethdev.c
> index 7cc083ca32..9478ba92df 100644
> --- a/drivers/net/intel/ice/ice_ethdev.c
> +++ b/drivers/net/intel/ice/ice_ethdev.c
> @@ -187,6 +187,7 @@ static int ice_timesync_read_time(struct rte_eth_dev *dev,
> static int ice_timesync_write_time(struct rte_eth_dev *dev,
> const struct timespec *timestamp);
> static int ice_timesync_disable(struct rte_eth_dev *dev);
> +static int eth_ice_read_clock(struct rte_eth_dev *dev, uint64_t *clock);
> static int ice_fec_get_capability(struct rte_eth_dev *dev, struct
> rte_eth_fec_capa *speed_fec_capa,
> unsigned int num);
> static int ice_fec_get(struct rte_eth_dev *dev, uint32_t *fec_capa);
> @@ -317,6 +318,7 @@ static const struct eth_dev_ops ice_eth_dev_ops = {
> .timesync_read_time = ice_timesync_read_time,
> .timesync_write_time = ice_timesync_write_time,
> .timesync_disable = ice_timesync_disable,
> + .read_clock = eth_ice_read_clock,
> .tm_ops_get = ice_tm_ops_get,
> .fec_get_capability = ice_fec_get_capability,
> .fec_get = ice_fec_get,
> @@ -6935,6 +6937,17 @@ ice_timesync_disable(struct rte_eth_dev *dev)
> return 0;
> }
>
> +static int
> +eth_ice_read_clock(__rte_unused struct rte_eth_dev *dev, uint64_t *clock)
> +{
> + struct timespec system_time;
> +
> + clock_gettime(CLOCK_REALTIME, &system_time);
> + *clock = system_time.tv_sec * NSEC_PER_SEC + system_time.tv_nsec;
> +
> + return 0;
> +}
> +
I see a number of problems here:
* The "read_clock" API is for reading the time from an ethernet device.
This is not the same a reading the system time and returning that.
* This uses a potential system call to read the time. (On some linux
implementations I think it will avoid a system call, but even so, we
should not add what may be a system call into these fast-path APIs)
/Bruce
