Closed boletus-edulis closed 4 months ago
You can also set
sysctl -w kernel.perf_user_access=2
to allow user mode access to rdcycle
. Just out of curiosity, which userland code are you referring to?
You can also set
sysctl -w kernel.perf_user_access=2
Ah ok, good to know, if i have time i might try that.
to allow user mode access to
rdcycle
. Just out of curiosity, which userland code are you referring to?
While bootstrapping NixOS, in particular some protobuf tests failed to run.
You can also set
sysctl -w kernel.perf_user_access=2
to allow user mode access to
rdcycle
. Just out of curiosity, which userland code are you referring to?
sysctl -w kernel.perf_user_access=2
Yes, this was needed. actually RISCV_PMU is enabled by default anyway. I don't know what i tested. Sorry for the noise.
I noticed that some userland apps are broken using sg2042-dev-6.6. I got SIGILL when using rdcycle instruction. By setting CONFIG_RISCV_PMU the code works again.
This was fixed in the following patch https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=cc4c07c89aada16229084eeb93895c95b7eabaa3
Although this is just a temporary solution, i would appreciate it if this patch could be accepted until the userland code gets fixed.