runtime: implement experiment to replace heap bitmap with alloc headers

[gostls13.git] / src / runtime / export_test.go

diff --git a/src/runtime/export_test.go b/src/runtime/export_test.go
index b60c1f0a69d1d44dc5bfa6c7f4e81865234556b1..f889c44b644a5cc684ae5278256a3151cc0368f5 100644 (file)
--- a/src/runtime/export_test.go
+++ b/src/runtime/export_test.go
@@ -9,6 +9,7 @@ package runtime
 import (
        "internal/abi"
        "internal/goarch"
+       "internal/goexperiment"
        "internal/goos"
        "runtime/internal/atomic"
        "runtime/internal/sys"
@@ -326,6 +327,14 @@ func BenchSetTypeSlice[T any](n int, resetTimer func(), len int) {
 // no valid racectx, but if we're instantiated in the runtime_test package,
 // we might accidentally cause runtime code to be incorrectly instrumented.
 func benchSetType(n int, resetTimer func(), len int, x unsafe.Pointer, t *_type) {
+       // This benchmark doesn't work with the allocheaders experiment. It sets up
+       // an elaborate scenario to be able to benchmark the function safely, but doing
+       // this work for the allocheaders' version of the function would be complex.
+       // Just fail instead and rely on the test code making sure we never get here.
+       if goexperiment.AllocHeaders {
+               panic("called benchSetType with allocheaders experiment enabled")
+       }
+
        // Compute the input sizes.
        size := t.Size() * uintptr(len)
 
@@ -340,7 +349,7 @@ func benchSetType(n int, resetTimer func(), len int, x unsafe.Pointer, t *_type)
 
        // Round up the size to the size class to make the benchmark a little more
        // realistic. However, validate it, to make sure this is safe.
-       allocSize := roundupsize(size)
+       allocSize := roundupsize(size, t.PtrBytes == 0)
        if s.npages*pageSize < allocSize {
                panic("backing span not large enough for benchmark")
        }