On Fri, Oct 30 2020 at 12:36, Thomas Gleixner wrote: > On Fri, Oct 30 2020 at 11:32, Peter Zijlstra wrote: > So the real question is what else is on that stack which blows it up > close to 4k? Btw, it would be massively helpful for this kind of crash > to print the actual stack depth per entry in the backtrace. > > Here is the partial stack trace: > Stack usage > ring_buffer_lock_reserve+0x12c/0x380 > trace_function+0x27/0x130 > function_trace_call+0x133/0x180 > perf_output_begin+0x4d/0x2d0 64+ > perf_log_throttle+0x9a/0x120 470+ > __perf_event_account_interrupt+0xa9/0x120 > __perf_event_overflow+0x2b/0xf0 > __intel_pmu_pebs_event+0x2ec/0x3e0 760+ > intel_pmu_drain_pebs_nhm+0x268/0x330 200+ > handle_pmi_common+0xc2/0x2b0
So Steven provided a backtrace with the actual stack depth printed: ring_buffer_lock_reserve+0x12c/0x380 0030 104 trace_function+0x27/0xf0 0098 56 function_trace_call+0x124/0x190 00d0 224 __rcu_read_lock+0x5/0x20 01b0 8 perf_output_begin+0x4d/0x2d0 01b8 640 perf_log_throttle+0x9a/0x120 0438 624 __perf_event_account_interrupt+0xa6/0x120 06a8 32 __perf_event_overflow+0x2b/0xf0 06c8 48 __intel_pmu_pebs_event+0x2ec/0x3e0 06f8 960 intel_pmu_drain_pebs_nhm+0x268/0x330 0ab8 256 handle_pmi_common+0xc2/0x2b0 0bb8 584 intel_pmu_handle_irq+0xc8/0x160 0e00 64 perf_event_nmi_handler+0x28/0x50 0e40 32 nmi_handle+0x80/0x190 0e60 64 default_do_nmi+0x6b/0x170 0ea0 40 exc_nmi+0x15d/0x1a0 0ec8 40 end_repeat_nmi+0x16/0x55 0ef0 272 So I missed perf_output_begin and handle_pmi_common ...
