diff options
| -rw-r--r-- | lib/kernel/test/os_SUITE.erl | 47 |
1 files changed, 27 insertions, 20 deletions
diff --git a/lib/kernel/test/os_SUITE.erl b/lib/kernel/test/os_SUITE.erl index 3cbb75a633..1233e362f2 100644 --- a/lib/kernel/test/os_SUITE.erl +++ b/lib/kernel/test/os_SUITE.erl @@ -319,31 +319,38 @@ perf_counter_api(_Config) -> true = is_integer(os:perf_counter()), true = os:perf_counter() > 0, - T1 = os:perf_counter(), + Conv = fun(T1, T2) -> + erlang:convert_time_unit(T2 - T1, perf_counter, nanosecond) + end, + + do_perf_counter_test([], Conv, 120000000, 80000000), + do_perf_counter_test([1000], fun(T1, T2) -> T2 - T1 end, 120, 80). + +do_perf_counter_test(CntArgs, Conv, Upper, Lower) -> + %% We run the test multiple times to try to get a somewhat + %% stable value... what does this test? That the + %% calculate_perf_counter_unit in sys_time.c works somewhat ok. + do_perf_counter_test(CntArgs, Conv, Upper, Lower, 10). + +do_perf_counter_test(CntArgs, _Conv, Upper, Lower, 0) -> + ct:fail("perf_counter_test ~p ~p ~p",[CntArgs, Upper, Lower]); +do_perf_counter_test(CntArgs, Conv, Upper, Lower, Iters) -> + + T1 = apply(os, perf_counter, CntArgs), timer:sleep(100), - T2 = os:perf_counter(), - TsDiff = erlang:convert_time_unit(T2 - T1, perf_counter, nanosecond), - ct:pal("T1: ~p~n" + T2 = apply(os, perf_counter, CntArgs), + TsDiff = Conv(T1, T2), + ct:log("T1: ~p~n" "T2: ~p~n" "TsDiff: ~p~n", [T1,T2,TsDiff]), - %% We allow a 15% diff - true = TsDiff < 115000000, - true = TsDiff > 85000000, - - T1Ms = os:perf_counter(1000), - timer:sleep(100), - T2Ms = os:perf_counter(1000), - MsDiff = T2Ms - T1Ms, - ct:pal("T1Ms: ~p~n" - "T2Ms: ~p~n" - "MsDiff: ~p~n", - [T1Ms,T2Ms,MsDiff]), - - %% We allow a 15% diff - true = MsDiff < 115, - true = MsDiff > 85. + if + TsDiff < Upper, TsDiff > Lower -> + ok; + true -> + do_perf_counter_test(CntArgs, Conv, Upper, Lower, Iters-1) + end. %% Util functions |