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| author | Yann Collet <cyan@fb.com> | 2018-02-20 21:05:22 (GMT) |
|---|---|---|
| committer | Yann Collet <cyan@fb.com> | 2018-02-20 21:09:13 (GMT) |
| commit | ae3dededed1c6c1a9b4c631d9edba690c4abb59c (patch) | |
| tree | 247aa24692ecbc82e1979269350e663a7a570c81 /programs/util.h | |
| parent | 1a233c5f0fb665fa6b65c856b150bdef92654b42 (diff) | |
| download | lz4-ae3dededed1c6c1a9b4c631d9edba690c4abb59c.zip lz4-ae3dededed1c6c1a9b4c631d9edba690c4abb59c.tar.gz lz4-ae3dededed1c6c1a9b4c631d9edba690c4abb59c.tar.bz2 | |
ensure bench speed measurement is more accurate for small inputs
Previous method would produce too many time() invocations,
becoming a significant fraction of workload measured.
The new strategy is to use time() only once per batch,
and dynamically resize batch size so that each round lasts approximately 1 second.
This only matters for small inputs.
Measurement for large files (such as silesia.tar) are much less impacted
(though decoding speed is so fast that even medium-size files will notice an improvement).
Diffstat (limited to 'programs/util.h')
| -rw-r--r-- | programs/util.h | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/programs/util.h b/programs/util.h index a3576d7..ff25106 100644 --- a/programs/util.h +++ b/programs/util.h @@ -180,7 +180,7 @@ extern "C" { mach_timebase_info(&rate); init = 1; } - return (((clockEnd - clockStart) * (U64)rate.numer) / ((U64)rate.denom))/1000ULL; + return (((clockEnd - clockStart) * (U64)rate.numer) / ((U64)rate.denom)) / 1000ULL; } UTIL_STATIC U64 UTIL_getSpanTimeNano(UTIL_time_t clockStart, UTIL_time_t clockEnd) { @@ -249,6 +249,12 @@ UTIL_STATIC U64 UTIL_clockSpanMicro(UTIL_time_t clockStart) return UTIL_getSpanTimeMicro(clockStart, clockEnd); } +/* returns time span in nanoseconds */ +UTIL_STATIC U64 UTIL_clockSpanNano(UTIL_time_t clockStart) +{ + UTIL_time_t const clockEnd = UTIL_getTime(); + return UTIL_getSpanTimeNano(clockStart, clockEnd); +} UTIL_STATIC void UTIL_waitForNextTick(void) { |