time: clean up benchmarks
Comparing BenchmarkStop against very old commits like
CL
13094043, I was very confused about how timers had
gotten almost 10X slower since 2013.
It turns out that CL
68060043 introduced a factor of 1000
in the benchmark cost, by counting batches of 1000 as 1 op
instead of 1000 ops, and timers have actually gotten
dramatically faster since 2013, with the addition of per-P
timer heaps and other optimizations.
This CL rewrites the benchmarks to use testing.PB directly,
so that the factor of 1000 disappears, and "/op" really means "/op".
In the few tests that need to run in batches for one reason or
another, add "1000" to the name to make clear that batches
are being run.
Change-Id: I27ed74d1e420934982e4205aad4f218cdfc42509
Reviewed-on: https://go-review.googlesource.com/c/go/+/570495
Auto-Submit: Russ Cox <rsc@golang.org>
Reviewed-by: Ian Lance Taylor <iant@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>