I try to use Instruction Based Sampling on a Dell poweredge R7425 machine equipped with 2 EPYC 7451 cpu running on Debian buster (Linux kernel 126.96.36.199, gcc 7.3.0), but neither µProf nor perf_event "see" that IBS is available:
- in µProf, in the "select configuration type", there's no "Instruction-based Sampling" configuration
- "perf list" does not show any ibs_op event, and when I try to use perf_event_open, I get "Invalid argument" errors
It seems that the problem is that Linux does not detect IBS: there's no /sys/devices/ibs_op entry in the filesystem, and I can't find any info related to IBS in dmesg output.
I saw on another thread (Instruction Based Sampling broken for Threadripper? ), that IBS may be enabled in BIOS, but I didn't find any option in my machine's BIOS.
I tried the AMD research instruction based sampling toolkit (GitHub - jlgreathouse/AMD_IBS_Toolkit: AMD Research Instruction Based Sampling Toolkit ), and it works, so IBS is indeed available, but not through Linux /sys/devices/ibs_op.
How could I make IBS work using perf ?