Hard lockup with timer events

[Soeren Sandmann]

Hi,

This program

        http://www.daimi.au.dk/~sandmann/lockup.c

locks up hard for me on a Pentium 4 in 32 bit mode, with the hrtimer
patches applied (-tip for example).

What the program does is spawn a thread that just spins, and then 400
threads that each create a performance counter of type
PERF_COUNT_SW_CPU_CLOCK and a sample period of 1000000 and a
sample_type of

        PERF_SAMPLE_IP | PERF_SAMPLE_TID | PERF_SAMPLE_CALLCHAIN

These threads then map the event buffer and read it continuously.

It does not apparently lock up if SAMPLE_CALLCHAIN is removed; also I
cannot get it to lock up on Core 2 Duo in either 32 or 64 bit mode.


Soren
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/