I get this same oops occassionally - the machine freezes and there doesn't seem to be any record of the oops on disk.
I captured it on camera - https://lh3.googleusercontent.com/-K0lNbJrZBMQ/UVOU1vv1vvI/AAAAAAAANqI/pY92mWm3caE/s800/20130327_205245.jpg If I am reading this right, it dies on this instruction - 0xffffffff8145792d <+349>: divq 0x18(%rcx) >From the lst file that *seems* to be this inline function - static inline void intel_pstate_calc_busy(struct cpudata *cpu, struct sample *sample) { u64 core_pct; sample->pstate_pct_busy = 100 - div64_u64( ffffffff8145791d: 48 8b 41 20 mov 0x20(%rcx),%rax ffffffff81457921: 48 8d 04 80 lea (%rax,%rax,4),%rax ffffffff81457925: 48 8d 04 80 lea (%rax,%rax,4),%rax ffffffff81457929: 48 c1 e0 02 shl $0x2,%rax ffffffff8145792d: 48 f7 71 18 divq 0x18(%rcx) That is - sample->pstate_pct_busy = 100 - div64_u64( sample->idletime_us * 100, sample->duration_us); So looks like sample->duration_us is 0? If so, that implies that ktime_us_delta(now, cpu->prev_sample) is zero. I am not entirely sure how to handle this case - return if sampling too early, or if there is some other bug making the delta calculation go poof. Thanks, Parag -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
