On Tue, May 23, 2023 at 01:06:16PM +0000, Anatoly Burakov wrote:
> Currently, it is allowed to specify a cpuset for lcores such that it
> will include physical cores from different NUMA nodes. This has an
> effect of setting `rte_socket_id()` for that lcore to SOCKET_ID_ANY,
> so add a warning about it.
>
> Signed-off-by: Anatoly Burakov <anatoly.bura...@intel.com>
> ---
> lib/eal/common/eal_common_thread.c | 20 +++++++++++++++++---
> 1 file changed, 17 insertions(+), 3 deletions(-)
>
> diff --git a/lib/eal/common/eal_common_thread.c
> b/lib/eal/common/eal_common_thread.c
> index 079a385630..46fd2aca1e 100644
> --- a/lib/eal/common/eal_common_thread.c
> +++ b/lib/eal/common/eal_common_thread.c
> @@ -65,10 +65,13 @@ static void
> thread_update_affinity(rte_cpuset_t *cpusetp)
> {
> unsigned int lcore_id = rte_lcore_id();
> + int socket_id;
> +
> + /* find socket ID from cpuset */
> + socket_id = eal_cpuset_socket_id(cpusetp);
>
> /* store socket_id in TLS for quick access */
> - RTE_PER_LCORE(_socket_id) =
> - eal_cpuset_socket_id(cpusetp);
> + RTE_PER_LCORE(_socket_id) = socket_id;
>
> /* store cpuset in TLS for quick access */
> memmove(&RTE_PER_LCORE(_cpuset), cpusetp,
> @@ -76,9 +79,20 @@ thread_update_affinity(rte_cpuset_t *cpusetp)
>
> if (lcore_id != (unsigned)LCORE_ID_ANY) {
> /* EAL thread will update lcore_config */
> - lcore_config[lcore_id].socket_id = RTE_PER_LCORE(_socket_id);
> + lcore_config[lcore_id].socket_id = socket_id;
> memmove(&lcore_config[lcore_id].cpuset, cpusetp,
> sizeof(rte_cpuset_t));
> +
> + /*
> + * lcore_id is not LCORE_ID_ANY, meaning this is a DPDK lcore,
> + * so having a valid NUMA affinity for this lcore is important.
> + * However, if cpuset includes cores from multiple NUMA nodes,
> + * the socket ID will be set to SOCKET_ID_ANY. Notify the user
> + * about it if that happens.
> + */
> + if (socket_id == SOCKET_ID_ANY)
> + RTE_LOG(INFO, EAL, "DPDK lcore %u has NUMA affinity set
> to SOCKET_ID_ANY\n",
> + lcore_id);
> }
> }
While having a warning comment in the code is good, should we not also have
a user visible warning to the user when the specific a corelist parameter
value which includes the cross-socket scenario?
/Bruce
