Ingo Molnar wrote:
> indeed it was broken - i fixed x64 LATENCY_TRACE in the -47-16 kernel.

There's a minor bug in it. Syscalls are numbered from zero, so there's 
__NR_syscall_max + 1 of them. Patch attached.
Nonetheless the latency tracing still doesn't work for me on x86_64. It 
compiles but hotplug starts to segfault in an infinite loop during 
booting up. When I disable CONFIG_LATENCY_TRACE, it works.

Michal