// Keep the first window.
					goto keep
				} else {
					// Replace it with this window.
					heap.Remove(&acc.wHeap, i)
					break
				}
			}
		}

		heap.Push(&acc.wHeap, UtilWindow{time, mu})
		if len(acc.wHeap) > acc.nWorst {
			heap.Pop(&acc.wHeap)
		}
	keep:
	}

	if len(acc.wHeap) < acc.nWorst {
		// We don't have N windows yet, so keep accumulating.
		acc.bound = 1.0
	} else {

// the ptr object regardless of the slot's color.
//
// Another place where we intentionally omit memory barriers is when
// accessing mheap_.arena_used to check if a pointer points into the
// heap. On relaxed memory machines, it's possible for a mutator to
// extend the size of the heap by updating arena_used, allocate an
// object from this new region, and publish a pointer to that object,

	var s *mspan
	systemstack(func() {
		lock(&mheap_.lock)
		s = (*mspan)(mheap_.spanalloc.alloc())
		unlock(&mheap_.lock)
	})
	return (*MSpan)(s)
}

// Free an allocated mspan.
func FreeMSpan(s *MSpan) {
	systemstack(func() {
		lock(&mheap_.lock)
		mheap_.spanalloc.free(unsafe.Pointer(s))
		unlock(&mheap_.lock)
	})
}

			s = stackLarge.free[log2npage].first
			stackLarge.free[log2npage].remove(s)
		}
		unlock(&stackLarge.lock)

		lockWithRankMayAcquire(&mheap_.lock, lockRankMheap)

		if s == nil {
			// Allocate a new stack from the heap.
			s = mheap_.allocManual(npage, spanAllocStack)
			if s == nil {
				throw("out of memory")
			}
			osStackAlloc(s)
			s.elemsize = uintptr(n)
		}

// output to a writer during profiling.
//
// # Heap profile
//
// The heap profile reports statistics as of the most recently completed
// garbage collection; it elides more recent allocation to avoid skewing
// the profile away from live data and toward garbage.
// If there has been no garbage collection at all, the heap profile reports
// all known allocations. This exception helps mainly in programs running

		#%           percentage of time spent in GC since program start
		#+...+#      wall-clock/CPU times for the phases of the GC
		#->#-># MB   heap size at GC start, at GC end, and live heap, or /gc/scan/heap:bytes
		# MB goal    goal heap size, or /gc/heap/goal:bytes
		# MB stacks  estimated scannable stack size, or /gc/scan/stack:bytes
		# MB globals scannable global size, or /gc/scan/globals:bytes

        false                    | MetadataFetchingCost.CHEAP     | MetadataFetchingCost.CHEAP
        false                    | MetadataFetchingCost.FAST      | MetadataFetchingCost.CHEAP
        false                    | MetadataFetchingCost.EXPENSIVE | MetadataFetchingCost.CHEAP
        true                     | MetadataFetchingCost.CHEAP     | MetadataFetchingCost.CHEAP

		Cumulative count of heap allocations whose storage was freed
		by the garbage collector. Note that this does not include tiny
		objects as defined by /gc/heap/tiny/allocs:objects, only tiny
		blocks.

	/gc/heap/goal:bytes
		Heap size target for the end of the GC cycle.

	/gc/heap/live:bytes
		Heap memory occupied by live objects that were marked by the
		previous GC.

	/gc/heap/objects:objects

	for i := range blocks {
		blocks[i] = new([blockSize]byte)
	}

	// Check that the running page count matches reality.
	pagesInUse, counted := runtime.CountPagesInUse()
	if pagesInUse != counted {
		t.Fatalf("mheap_.pagesInUse is %d, but direct count is %d", pagesInUse, counted)
	}
}

func init() {
	// Enable ReadMemStats' double-check mode.
	*runtime.DoubleCheckReadMemStats = true
}

	// Experimental heap span events. Added in Go 1.23.
	EvSpan      // heap span exists [timestamp, id, npages, type/class]
	EvSpanAlloc // heap span alloc [timestamp, id, npages, type/class]
	EvSpanFree  // heap span free [timestamp, id]

	// Experimental heap object events. Added in Go 1.23.
	EvHeapObject      // heap object exists [timestamp, id, type]
	EvHeapObjectAlloc // heap object alloc [timestamp, id, type]