** Description changed: [Impact] Currently Ubuntu kernel has this kernel config disabled. But in some cases, Intel's Sapphire Rapids High Bandwith Memory (SPR-HBM) needs this option. Memory bandwidth has been a bottleneck of increasingly memory bound workloads. Sapphire Rapids plus HBM is specifically targeted to cater to these workloads, traditionally served using overprovisioning of memory devices. Please search the keyword "fake numa" in https://community.intel.com/t5/Blogs/Products-and- Solutions/HPC/Enabling-High-Bandwidth-Memory-for-HPC-and-AI- Applications-for/post/1335100 [Fix] Enable CONFIG_NUMA_EMU in our kernel config for 5.15 and later [Test Plan] Use "STREAM-triadd" algorithm* in Intel MLC** to benchmark 3 scenarios (no fake NUMA, 2U fake NUMA and 4U fake NUMA). * https://www.intel.com/content/www/us/en/developer/articles/technical/optimizing-memory-bandwidth-on-stream-triad.html ** https://www.intel.com/content/www/us/en/download/736633/intel-memory-latency-checker-intel-mlc.html An improvement to performance on a Sapphire Rapids CPU with HBM should be observed [Where problems could occur] The regression risk is low [Other Info] Jammy - https://code.launchpad.net/~mreed8855/ubuntu/+source/linux/+git/jammy/+ref/lp_2008745_config_numa_emu + https://code.launchpad.net/~mreed8855/ubuntu/+source/linux/+git/jammy/+ref/lp_2008745_config_numa_emu_2 Kinetic https://code.launchpad.net/~mreed8855/ubuntu/+source/linux/+git/kinetic/+ref/lp_2008745_config_numa_emu_kinetic Lunar https://code.launchpad.net/~mreed8855/ubuntu/+source/linux/+git/lunar/+ref/config_numa_emu_lunar_2
-- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/2008745 Title: [SRU] Intel Sapphire Rapids HBM support needs CONFIG_NUMA_EMU Status in linux package in Ubuntu: In Progress Status in linux source package in Jammy: In Progress Status in linux source package in Kinetic: In Progress Status in linux source package in Lunar: In Progress Bug description: [Impact] Currently Ubuntu kernel has this kernel config disabled. But in some cases, Intel's Sapphire Rapids High Bandwith Memory (SPR-HBM) needs this option. Memory bandwidth has been a bottleneck of increasingly memory bound workloads. Sapphire Rapids plus HBM is specifically targeted to cater to these workloads, traditionally served using overprovisioning of memory devices. Please search the keyword "fake numa" in https://community.intel.com/t5/Blogs/Products-and- Solutions/HPC/Enabling-High-Bandwidth-Memory-for-HPC-and-AI- Applications-for/post/1335100 [Fix] Enable CONFIG_NUMA_EMU in our kernel config for 5.15 and later [Test Plan] Use "STREAM-triadd" algorithm* in Intel MLC** to benchmark 3 scenarios (no fake NUMA, 2U fake NUMA and 4U fake NUMA). * https://www.intel.com/content/www/us/en/developer/articles/technical/optimizing-memory-bandwidth-on-stream-triad.html ** https://www.intel.com/content/www/us/en/download/736633/intel-memory-latency-checker-intel-mlc.html An improvement to performance on a Sapphire Rapids CPU with HBM should be observed [Where problems could occur] The regression risk is low [Other Info] Jammy https://code.launchpad.net/~mreed8855/ubuntu/+source/linux/+git/jammy/+ref/lp_2008745_config_numa_emu_2 Kinetic https://code.launchpad.net/~mreed8855/ubuntu/+source/linux/+git/kinetic/+ref/lp_2008745_config_numa_emu_kinetic Lunar https://code.launchpad.net/~mreed8855/ubuntu/+source/linux/+git/lunar/+ref/config_numa_emu_lunar_2 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2008745/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
