>On 22-Jun-18 5:37 PM, Kumar, Ravi1 wrote: >> Hi, >> >> As the memory subsystem in DPDK 18.05 is reworked, it has introduced a >> problem for AMD EPYC 2P platforms. >> The issue is that DPDK 18.05 only works with up to 4 NUMAs. For AMD EPYC 2P >> platforms, DPDK now only works with P0 (NUMA 0-3) and does not work with P1 >> (NUMA 4-7). >> >> The problem can be fixed by reducing some of the default settings of the >> memory subsystem. >> >> To solve this issue: >> - We can create our own config file for our integrated 10G NIC, >> that is for amd_xgbe PMD. This will make amd_xgbe immune to this problem. >> - However, when any other NIC (Intel, Mellanox, Cavium or >> Broadcom etc.) is plugged into NUMA 4-7, the problem will still be exposed. >> - If we only fix it in "config/common_base", it will cover all >> cases. >> >> Our current workaround is: >> Edit config file "./config/common_base" and change the following line >> CONFIG_RTE_MAX_MEM_MB_PER_TYPE=131072 >> TO >> CONFIG_RTE_MAX_MEM_MB_PER_TYPE=65536 >> >> Any better solution for this issue is welcome. >> >> We would appreciate if this issue can be fixed in the next release (18.08) >> so the STOCK version of DPDK works on AMD EPYC 2P platforms. >> >> Regards, >> Ravi >> > >Hi Ravi, > >What is the reason behind this limitation? Is it too much virtual memory being >preallocated? > >-- >Thanks, >Anatoly > Hi Anatoly,
We believe this is true. By default, too much virtual memory is being preallocated. The result is it can only support up to 4 NUMAs. Our workaround is to reduce the amount of preallocated virtual memory by half, so to support up to 8 NUMAs. Regards, Ravi
