From 0f698be54742be2d66c044b61267782272777ff8 Mon Sep 17 00:00:00 2001 From: Russ Cox Date: Mon, 27 Oct 2014 18:59:02 -0400 Subject: [PATCH] test: make maplinear more robust The test just doubled a certain number of times and then gave up. On a mostly fast but occasionally slow machine this may never make the test run long enough to see the linear growth. Change test to keep doubling until the first round takes at least a full second, to reduce the effect of occasional scheduling or other jitter. The failure we saw had a time for the first round of around 100ms. Note that this test still passes once it sees a linear effect, even with a very small total time. The timeout here only applies to how long the execution must be to support a reported failure. LGTM=khr R=khr CC=golang-codereviews, rlh https://golang.org/cl/164070043 --- test/maplinear.go | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) diff --git a/test/maplinear.go b/test/maplinear.go index 06da968ef0..34d0914914 100644 --- a/test/maplinear.go +++ b/test/maplinear.go @@ -44,14 +44,21 @@ func checkLinear(typ string, tries int, f func(n int)) { } return } - fails++ - if fails == 6 { + // If n ops run in under a second and the ratio + // doesn't work out, make n bigger, trying to reduce + // the effect that a constant amount of overhead has + // on the computed ratio. + if t1 < 1*time.Second { + n *= 2 + continue + } + // Once the test runs long enough for n ops, + // try to get the right ratio at least once. + // If five in a row all fail, give up. + if fails++; fails >= 5 { panic(fmt.Sprintf("%s: too slow: %d inserts: %v; %d inserts: %v\n", typ, n, t1, 2*n, t2)) } - if fails < 4 { - n *= 2 - } } } -- 2.50.0