diff options
Diffstat (limited to 'src/runtime/mpagealloc.go')
| -rw-r--r-- | src/runtime/mpagealloc.go | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/src/runtime/mpagealloc.go b/src/runtime/mpagealloc.go index f48b9faec3..10d547296e 100644 --- a/src/runtime/mpagealloc.go +++ b/src/runtime/mpagealloc.go @@ -245,6 +245,19 @@ type pageAlloc struct { // currently ready to use. start, end chunkIdx + // inUse is a slice of ranges of address space which are + // known by the page allocator to be currently in-use (passed + // to grow). + // + // This field is currently unused on 32-bit architectures but + // is harmless to track. We care much more about having a + // contiguous heap in these cases and take additional measures + // to ensure that, so in nearly all cases this should have just + // 1 element. + // + // All access is protected by the mheapLock. + inUse addrRanges + // mheap_.lock. This level of indirection makes it possible // to test pageAlloc indepedently of the runtime allocator. mheapLock *mutex @@ -268,6 +281,9 @@ func (s *pageAlloc) init(mheapLock *mutex, sysStat *uint64) { } s.sysStat = sysStat + // Initialize s.inUse. + s.inUse.init(sysStat) + // System-dependent initialization. s.sysInit() @@ -381,6 +397,10 @@ func (s *pageAlloc) grow(base, size uintptr) { if end > s.end { s.end = end } + // Note that [base, limit) will never overlap with any existing + // range inUse because grow only ever adds never-used memory + // regions to the page allocator. + s.inUse.add(addrRange{base, limit}) // A grow operation is a lot like a free operation, so if our // chunk ends up below the (linearized) s.searchAddr, update |