Re: [PATCH 2/3] perf/x86/intel: fix for MSR_LAST_BRANCH_FROM_x quirk when no TSX

[Andi Kleen]

>   $ ./lbr_perf record --call-graph lbr -e cycles:k ./cqm_easy
> 
> where lbr_perf is the patched perf tool, that allows to specify :k
> on lbr mode. The above command will trigger a #GPF :

Why would you want to do that? We usually have frame pointers for
the kernel, so callstack LBR for the kernel is pointless.

-Andi