On Mon, May 02, 2016 at 01:37:45PM +0530, Jerin Jacob wrote:
> Elements of struct rte_eth_dev used in the fast path.
> Make struct rte_eth_dev cache aligned to avoid the cases where
> rte_eth_dev elements share the same cache line with other structures.
>
> Signed-off-by: Jerin Jacob <jerin.jacob at caviumnetworks.com>
> ---
> lib/librte_ether/rte_ethdev.c | 2 +-
> lib/librte_ether/rte_ethdev.h | 2 +-
> 2 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/lib/librte_ether/rte_ethdev.c b/lib/librte_ether/rte_ethdev.c
> index a31018e..04f492d 100644
> --- a/lib/librte_ether/rte_ethdev.c
> +++ b/lib/librte_ether/rte_ethdev.c
> @@ -70,7 +70,7 @@
> #include "rte_ethdev.h"
>
> static const char *MZ_RTE_ETH_DEV_DATA = "rte_eth_dev_data";
> -struct rte_eth_dev rte_eth_devices[RTE_MAX_ETHPORTS];
> +struct rte_eth_dev rte_eth_devices[RTE_MAX_ETHPORTS] __rte_cache_aligned;
> static struct rte_eth_dev_data *rte_eth_dev_data;
> static uint8_t nb_ports;
>
> diff --git a/lib/librte_ether/rte_ethdev.h b/lib/librte_ether/rte_ethdev.h
> index 8519ff6..e359dda 100644
> --- a/lib/librte_ether/rte_ethdev.h
> +++ b/lib/librte_ether/rte_ethdev.h
> @@ -1630,7 +1630,7 @@ struct rte_eth_dev {
> struct rte_eth_rxtx_callback *pre_tx_burst_cbs[RTE_MAX_QUEUES_PER_PORT];
> uint8_t attached; /**< Flag indicating the port is attached */
> enum rte_eth_dev_type dev_type; /**< Flag indicating the device type */
> -};
> +} __rte_cache_aligned;
>
> struct rte_eth_dev_sriov {
> uint8_t active; /**< SRIOV is active with 16, 32 or 64
> pools */
> --
Adding cache aligned in two places is overkill, I think. If the structure is
marked as being cache aligned, there is no need to have the rte_eth_devices
marked that way too. I suggest therefore just keeping the structure alignment.
Regards,
/Bruce
