** Description changed: [Impact] Applications, particularly those in the HPC domain (e.g. openmpi), can be optimized for the processor and cache topology. However, the ARM CPU topology isn't correctly exposed to userspace. [Fix] The ACPI 6.2 specification introduced a Processor Properties Topology Table (PPTT). The linux kernel needs support for parsing this table, and exposing the parsed topology to userspace. + [Test Case] - TBD + A HiSilicon D06 without the fix: + + ubuntu@d06-1:~$ lscpu + Architecture: aarch64 + Byte Order: Little Endian + CPU(s): 96 + On-line CPU(s) list: 0-95 + Thread(s) per core: 1 + Core(s) per socket: 4 + Socket(s): 24 + NUMA node(s): 4 + Vendor ID: 0x48 + Model: 0 + Stepping: 0x0 + BogoMIPS: 200.00 + NUMA node0 CPU(s): 0-23 + NUMA node1 CPU(s): 24-47 + NUMA node2 CPU(s): 48-71 + NUMA node3 CPU(s): 72-95 + Flags: fp asimd evtstrm aes pmull sha1 sha2 crc32 atomics cpuid asimdrdm dcpop + + With the fix: + ubuntu@d06-1:~$ lscpu + Architecture: aarch64 + Byte Order: Little Endian + CPU(s): 96 + On-line CPU(s) list: 0-95 + Thread(s) per core: 1 + Core(s) per socket: 48 + Socket(s): 2 + NUMA node(s): 4 + Vendor ID: 0x48 + Model: 0 + Stepping: 0x0 + BogoMIPS: 200.00 + L1d cache: 64K + L1i cache: 64K + L2 cache: 512K + L3 cache: 32768K + NUMA node0 CPU(s): 0-23 + NUMA node1 CPU(s): 24-47 + NUMA node2 CPU(s): 48-71 + NUMA node3 CPU(s): 72-95 + Flags: fp asimd evtstrm aes pmull sha1 sha2 crc32 atomics cpuid asimdrdm dcpop + [Regression Risk] TBD
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1770231 Title: Expose arm64 CPU topology to userspace To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1770231/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
