On 9/23/14, 12:00 PM, Namhyung Kim wrote: > + unw_set_caching_policy(addr_space, UNW_CACHE_GLOBAL);
The result is a bit surprising for me. In micro benchmarking (eg: Lperf-simple), the per-thread policy is generally faster because it doesn't involve locking. libunwind/tests/Lperf-simple unw_getcontext : cold avg= 109.673 nsec, warm avg= 28.610 nsec unw_init_local : cold avg= 259.876 nsec, warm avg= 9.537 nsec no cache : unw_step : 1st= 3258.387 min= 2922.331 avg= 3002.384 nsec global cache : unw_step : 1st= 1192.093 min= 960.486 avg= 982.208 nsec per-thread cache: unw_step : 1st= 429.153 min= 113.533 avg= 121.762 nsec I can see how the global policy would involve less memory allocation because of shared data structures. Curious about the reason for the speedup (specifically if libunwind should change the defaults for the non-local unwinding case). -Arun -- 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/
