runtime/metrics: mark histogram metrics as cumulative

All the current histogram metrics accumulate counts from program start
to infinity, and can be reasonably used to compute rates (also to
generate windowed distributions).

Change-Id: I5196c59867de34fba41bb8552606fa315460cef9
Reviewed-on: https://go-review.googlesource.com/c/go/+/282633
Run-TryBot: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Trust: Michael Knyszek <mknyszek@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>
Reviewed-by: Austin Clements <austin@google.com>

diff --git a/src/runtime/metrics/description.go b/src/runtime/metrics/description.go
index 716802e9a2f9fe43a8a17cdb516dc8b0457cb6e2..117515610436f2a27145a79f589400d8076e14b3 100644 (file)
--- a/src/runtime/metrics/description.go
+++ b/src/runtime/metrics/description.go
@@ -73,11 +73,13 @@ var allDesc = []Description{
                Name:        "/gc/heap/allocs-by-size:bytes",
                Description: "Distribution of all objects allocated by approximate size.",
                Kind:        KindFloat64Histogram,
+               Cumulative:  true,
        },
        {
                Name:        "/gc/heap/frees-by-size:bytes",
                Description: "Distribution of all objects freed by approximate size.",
                Kind:        KindFloat64Histogram,
+               Cumulative:  true,
        },
        {
                Name:        "/gc/heap/goal:bytes",
@@ -93,6 +95,7 @@ var allDesc = []Description{
                Name:        "/gc/pauses:seconds",
                Description: "Distribution individual GC-related stop-the-world pause latencies.",
                Kind:        KindFloat64Histogram,
+               Cumulative:  true,
        },
        {
                Name: "/memory/classes/heap/free:bytes",