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authortomsmeding <tom.smeding@gmail.com>2018-12-15 20:02:32 +0100
committertomsmeding <tom.smeding@gmail.com>2018-12-15 20:02:32 +0100
commitac044d8bb94940cf479e10eefa946c30db2a811c (patch)
treee386e319436fb2620aebe0c8c41dd718b49757cd /2018
parentca19e1d4aac6d2da8dae9b60f5b13962b7aff0b8 (diff)
Make benchmark module less incorrect
Diffstat (limited to '2018')
-rw-r--r--2018/src/benchmark.rs45
1 files changed, 30 insertions, 15 deletions
diff --git a/2018/src/benchmark.rs b/2018/src/benchmark.rs
index 76de9e4..697fa8e 100644
--- a/2018/src/benchmark.rs
+++ b/2018/src/benchmark.rs
@@ -7,13 +7,13 @@ const MIN_TIMES: usize = 4;
pub struct Bench {
pub executions: usize,
pub duration: f64,
- pub duration_stddev: f64,
+ pub duration_stderr: f64,
}
impl fmt::Display for Bench {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "{} secs ± {} ({}%)",
- self.duration, self.duration_stddev, self.duration_stddev / self.duration * 100.0)
+ self.duration, self.duration_stderr, self.duration_stderr / self.duration * 100.0)
}
}
@@ -51,28 +51,43 @@ pub fn benchmark<A, F: Fn() -> A>(func: F) -> Bench {
let nparts = if ntimes_guess < 10 {
ntimes_guess
} else {
- std::cmp::max(10, ntimes_guess / 10)
+ std::cmp::max(10, ntimes_guess / 100)
};
let nperpart = (ntimes_guess + nparts - 1) / nparts;
- let ntimes = nparts * nperpart;
-
// eprintln!("BENCH: estimate={} ntimes_guess={} nparts={} nperpart={} ntimes={}", estimate, ntimes_guess, nparts, nperpart, ntimes);
- let mut times = vec![0.0; nparts];
+ let mut times = Vec::new();
- for i in 0..nparts {
- let start = Instant::now();
- for _ in 0..nperpart {
- func();
+ let mut mean = 0.0;
+ let mut stderr = 0.0;
+
+ eprint!("BENCH: Running {} blocks of {} calls...", nparts, nperpart);
+
+ for _ in 0..6 {
+ for _ in 0..nparts {
+ let start = Instant::now();
+ for _ in 0..nperpart {
+ func();
+ }
+ let end = Instant::now();
+
+ times.push(duration_secs(end - start));
+ }
+
+ let partmean = times.iter().map(|&t| t).sum::<f64>() / times.len() as f64;
+ let stddev = (times.iter().map(|&t| (t - partmean) * (t - partmean)).sum::<f64>() / (times.len() - 1) as f64).sqrt();
+ stderr = stddev / (times.len() as f64).sqrt();
+ mean = partmean / nperpart as f64;
+
+ if stderr / mean < 0.05 {
+ break;
}
- let end = Instant::now();
- times[i] = duration_secs(end - start);
+ eprint!(" again({},{})", mean, stderr);
}
- let mean = times.iter().map(|&t| t).sum::<f64>() / ntimes as f64;
- let stddev = times.iter().map(|t| (t - mean) * (t - mean)).sum::<f64>() / (ntimes - 1) as f64;
+ eprintln!("");
- Bench { executions: 0, duration: mean, duration_stddev: stddev }
+ Bench { executions: times.len() * nperpart, duration: mean, duration_stderr: stderr }
}