On Thu, Feb 4, 2021 at 3:58 PM Thomas Monjalon <tho...@monjalon.net> wrote: > > 04/02/2021 07:19, Jerin Jacob: > > On Thu, Feb 4, 2021 at 2:49 AM Thomas Monjalon <tho...@monjalon.net> wrote: > > > > > > AMD CPU can present a high number of NUMA nodes. > > > The default should be 32 for better compatibility. > > > > The typical configuration is 4 nodes[1] for AMD. Just wondering, Is it > > an exception case? if so, Do we need to consume more memory for normal > > cases? > > > > [1] > > https://developer.amd.com/wp-content/resources/56308-NUMA%20Topology%20for%20AMD%20EPYC%E2%84%A2%20Naples%20Family%20Processors.PDF > > As you can read in > https://www.dell.com/support/kbdoc/fr-fr/000137696/amd-rome-is-it-for-real-architecture-and-initial-hpc-performance > there is an option "CCX as NUMA Domain. > This option exposes each CCX as a NUMA node. > On a system with dual-socket CPUs with 16 CCXs per CPU, > this setting will expose 32 NUMA domains." > and > "Enabling this option is expected to help virtualized environments."
I see. > > I would not say it is exceptional. > And in my understanding, the memory cost is not so high for DPDK. > Do you see some large arrays depending on RTE_MAX_NUMA_NODES? Not quite a lot. lib/librte_efd/rte_efd.c: struct efd_online_chunk *chunks[RTE_MAX_NUMA_NODES]; lib/librte_eal/linux/eal_memory.c: uint64_t memory[RTE_MAX_NUMA_NODES]; lib/librte_eal/linux/eal.c: char * arg[RTE_MAX_NUMA_NODES]; lib/librte_eal/common/eal_common_dynmem.c: uint64_t memory[RTE_MAX_NUMA_NODES]; lib/librte_eal/common/eal_common_dynmem.c: int cpu_per_socket[RTE_MAX_NUMA_NODES]; lib/librte_eal/common/eal_private.h: uint32_t numa_nodes[RTE_MAX_NUMA_NODES]; /**< List of detected NUMA nodes. */ lib/librte_eal/common/eal_internal_cfg.h: uint32_t num_pages[RTE_MAX_NUMA_NODES]; lib/librte_eal/common/eal_internal_cfg.h: volatile uint64_t socket_mem[RTE_MAX_NUMA_NODES]; /**< amount of memory per socket */ lib/librte_eal/common/eal_internal_cfg.h: volatile uint64_t socket_limit[RTE_MAX_NUMA_NODES]; /**< limit amount of memory per socket */ lib/librte_eal/windows/eal_lcore.c: struct socket_map sockets[RTE_MAX_NUMA_NODES]; lib/librte_node/ip4_lookup.c: struct rte_lpm *lpm_tbl[RTE_MAX_NUMA_NODES]; Acked-by: Jerin Jacob <jer...@marvell.com> > >
