diff options
Diffstat (limited to 'src/runtime/malloc.go')
| -rw-r--r-- | src/runtime/malloc.go | 37 |
1 files changed, 26 insertions, 11 deletions
diff --git a/src/runtime/malloc.go b/src/runtime/malloc.go index c7ab928fe6..ce03114edc 100644 --- a/src/runtime/malloc.go +++ b/src/runtime/malloc.go @@ -1221,12 +1221,7 @@ func mallocgc(size uintptr, typ *_type, needzero bool) unsafe.Pointer { // This may be racing with GC so do it atomically if there can be // a race marking the bit. if gcphase != _GCoff { - // Pass the full size of the allocation to the number of bytes - // marked. - // - // If !goexperiment.AllocHeaders, "size" doesn't include the - // allocation header, so use span.elemsize unconditionally. - gcmarknewobject(span, uintptr(x), span.elemsize) + gcmarknewobject(span, uintptr(x)) } if raceenabled { @@ -1248,12 +1243,28 @@ func mallocgc(size uintptr, typ *_type, needzero bool) unsafe.Pointer { asanunpoison(x, userSize) } + // If !goexperiment.AllocHeaders, "size" doesn't include the + // allocation header, so use span.elemsize as the "full" size + // for various computations below. + // + // TODO(mknyszek): We should really count the header as part + // of gc_sys or something, but it's risky to change the + // accounting so much right now. Just pretend its internal + // fragmentation and match the GC's accounting by using the + // whole allocation slot. + fullSize := size + if goexperiment.AllocHeaders { + fullSize = span.elemsize + } if rate := MemProfileRate; rate > 0 { // Note cache c only valid while m acquired; see #47302 - if rate != 1 && size < c.nextSample { - c.nextSample -= size + // + // N.B. Use the full size because that matches how the GC + // will update the mem profile on the "free" side. + if rate != 1 && fullSize < c.nextSample { + c.nextSample -= fullSize } else { - profilealloc(mp, x, size) + profilealloc(mp, x, fullSize) } } mp.mallocing = 0 @@ -1268,6 +1279,7 @@ func mallocgc(size uintptr, typ *_type, needzero bool) unsafe.Pointer { if goexperiment.AllocHeaders && header != nil { throw("unexpected malloc header in delayed zeroing of large object") } + // N.B. size == fullSize always in this case. memclrNoHeapPointersChunked(size, x) // This is a possible preemption point: see #47302 } @@ -1278,14 +1290,17 @@ func mallocgc(size uintptr, typ *_type, needzero bool) unsafe.Pointer { if inittrace.active && inittrace.id == getg().goid { // Init functions are executed sequentially in a single goroutine. - inittrace.bytes += uint64(size) + inittrace.bytes += uint64(fullSize) } } if assistG != nil { // Account for internal fragmentation in the assist // debt now that we know it. - assistG.gcAssistBytes -= int64(size - dataSize) + // + // N.B. Use the full size because that's how the rest + // of the GC accounts for bytes marked. + assistG.gcAssistBytes -= int64(fullSize - dataSize) } if shouldhelpgc { |