diff options
Diffstat (limited to 'src/runtime/mksizeclasses.go')
| -rw-r--r-- | src/runtime/mksizeclasses.go | 13 |
1 files changed, 8 insertions, 5 deletions
diff --git a/src/runtime/mksizeclasses.go b/src/runtime/mksizeclasses.go index 0cb2b33a8c..b146dbcd6c 100644 --- a/src/runtime/mksizeclasses.go +++ b/src/runtime/mksizeclasses.go @@ -24,8 +24,8 @@ // In practice, only one of the wastes comes into play for a // given size (sizes < 512 waste mainly on the round-up, // sizes > 512 waste mainly on the page chopping). -// -// TODO(rsc): Compute max waste for any given size. +// For really small sizes, alignment constraints force the +// overhead higher. package main @@ -242,15 +242,18 @@ nextk: } func printComment(w io.Writer, classes []class) { - fmt.Fprintf(w, "// %-5s %-9s %-10s %-7s %-11s\n", "class", "bytes/obj", "bytes/span", "objects", "waste bytes") + fmt.Fprintf(w, "// %-5s %-9s %-10s %-7s %-10s %-9s\n", "class", "bytes/obj", "bytes/span", "objects", "tail waste", "max waste") + prevSize := 0 for i, c := range classes { if i == 0 { continue } spanSize := c.npages * pageSize objects := spanSize / c.size - waste := spanSize - c.size*(spanSize/c.size) - fmt.Fprintf(w, "// %5d %9d %10d %7d %11d\n", i, c.size, spanSize, objects, waste) + tailWaste := spanSize - c.size*(spanSize/c.size) + maxWaste := float64((c.size-prevSize-1)*objects+tailWaste) / float64(spanSize) + prevSize = c.size + fmt.Fprintf(w, "// %5d %9d %10d %7d %10d %8.2f%%\n", i, c.size, spanSize, objects, tailWaste, 100*maxWaste) } fmt.Fprintf(w, "\n") } |