Commit fe6e77f6 authored by Kostya Kortchinsky's avatar Kostya Kortchinsky
Browse files

[scudo][standalone] 32-bit improvement 

Summary:
This tweaks some behaviors of the allocator wrt 32-bit, notably
tailoring the size-class map.

I had to remove a `printStats` from `__scudo_print_stats` since when
within Bionic they share the same slot so they can't coexist at the
same time. I have to find a solution for that later, but right now we
are not using the Svelte configuration.

Reviewers: rengolin

Subscribers: #sanitizers, llvm-commits

Tags: #sanitizers, #llvm

Differential Revision: https://reviews.llvm.org/D74178
parent 609a489e

compiler-rt/lib/scudo/standalone/primary32.h

+20 −18
Original line number Diff line number Diff line
@@ -41,6 +41,8 @@ namespace scudo { 
template <class SizeClassMapT, uptr RegionSizeLog> class SizeClassAllocator32 {

public:

  typedef SizeClassMapT SizeClassMap;

  // The bytemap can only track UINT8_MAX - 1 classes.

  static_assert(SizeClassMap::LargestClassId <= (UINT8_MAX - 1), "");

  // Regions should be large enough to hold the largest Block.

  static_assert((1UL << RegionSizeLog) >= SizeClassMap::MaxSize, "");

  typedef SizeClassAllocator32<SizeClassMapT, RegionSizeLog> ThisT;
@@ -87,8 +89,7 @@ public: 
    while (NumberOfStashedRegions > 0)

      unmap(reinterpret_cast<void *>(RegionsStash[--NumberOfStashedRegions]),

            RegionSize);

    // TODO(kostyak): unmap the TransferBatch regions as well.

    for (uptr I = 0; I < NumRegions; I++)

    for (uptr I = MinRegionIndex; I <= MaxRegionIndex; I++)

      if (PossibleRegions[I])

        unmap(reinterpret_cast<void *>(I * RegionSize), RegionSize);

    PossibleRegions.unmapTestOnly();
@@ -147,8 +148,9 @@ public: 


  template <typename F> void iterateOverBlocks(F Callback) {

    for (uptr I = MinRegionIndex; I <= MaxRegionIndex; I++)

      if (PossibleRegions[I]) {

        const uptr BlockSize = getSizeByClassId(PossibleRegions[I]);

      if (PossibleRegions[I] &&

          (PossibleRegions[I] - 1U) != SizeClassMap::BatchClassId) {

        const uptr BlockSize = getSizeByClassId(PossibleRegions[I] - 1U);

        const uptr From = I * RegionSize;

        const uptr To = From + (RegionSize / BlockSize) * BlockSize;

        for (uptr Block = From; Block < To; Block += BlockSize)
@@ -258,14 +260,12 @@ private: 
    if (!Region)

      Region = allocateRegionSlow();

    if (LIKELY(Region)) {

      if (ClassId) {

      const uptr RegionIndex = computeRegionId(Region);

      if (RegionIndex < MinRegionIndex)

        MinRegionIndex = RegionIndex;

      if (RegionIndex > MaxRegionIndex)

        MaxRegionIndex = RegionIndex;

        PossibleRegions.set(RegionIndex, static_cast<u8>(ClassId));

      }

      PossibleRegions.set(RegionIndex, static_cast<u8>(ClassId + 1U));

    }

    return Region;

  }
@@ -350,10 +350,10 @@ private: 
    const uptr InUse = Sci->Stats.PoppedBlocks - Sci->Stats.PushedBlocks;

    const uptr AvailableChunks = Sci->AllocatedUser / getSizeByClassId(ClassId);

    Str->append("  %02zu (%6zu): mapped: %6zuK popped: %7zu pushed: %7zu "

                "inuse: %6zu avail: %6zu rss: %6zuK\n",

                "inuse: %6zu avail: %6zu rss: %6zuK releases: %6zu\n",

                ClassId, getSizeByClassId(ClassId), Sci->AllocatedUser >> 10,

                Sci->Stats.PoppedBlocks, Sci->Stats.PushedBlocks, InUse,

                AvailableChunks, Rss >> 10);

                AvailableChunks, Rss >> 10, Sci->ReleaseInfo.RangesReleased);

  }



  NOINLINE uptr releaseToOSMaybe(SizeClassInfo *Sci, uptr ClassId,
@@ -389,10 +389,11 @@ private: 
    // regions. But it will have to do for now.

    uptr TotalReleasedBytes = 0;

    for (uptr I = MinRegionIndex; I <= MaxRegionIndex; I++) {

      if (PossibleRegions[I] == ClassId) {

        ReleaseRecorder Recorder(I * RegionSize);

        releaseFreeMemoryToOS(Sci->FreeList, I * RegionSize,

                              RegionSize / PageSize, BlockSize, &Recorder);

      if (PossibleRegions[I] - 1U == ClassId) {

        const uptr Region = I * RegionSize;

        ReleaseRecorder Recorder(Region);

        releaseFreeMemoryToOS(Sci->FreeList, Region, RegionSize / PageSize,

                              BlockSize, &Recorder);

        if (Recorder.getReleasedRangesCount() > 0) {

          Sci->ReleaseInfo.PushedBlocksAtLastRelease = Sci->Stats.PushedBlocks;

          Sci->ReleaseInfo.RangesReleased += Recorder.getReleasedRangesCount();
@@ -407,6 +408,7 @@ private: 


  SizeClassInfo SizeClassInfoArray[NumClasses];



  // Track the regions in use, 0 is unused, otherwise store ClassId + 1.

  ByteMap PossibleRegions;

  // Keep track of the lowest & highest regions allocated to avoid looping

  // through the whole NumRegions.

compiler-rt/lib/scudo/standalone/size_class_map.h

+1 −1
Original line number Diff line number Diff line
@@ -144,7 +144,7 @@ typedef SizeClassMap<4, 4, 8, 14, 4, 10> SvelteSizeClassMap; 
typedef SizeClassMap<2, 5, 9, 16, 14, 14> AndroidSizeClassMap;

#else

typedef SizeClassMap<4, 3, 7, 14, 5, 10> SvelteSizeClassMap;

typedef SizeClassMap<2, 5, 9, 16, 14, 14> AndroidSizeClassMap;

typedef SizeClassMap<3, 4, 9, 16, 14, 14> AndroidSizeClassMap;

#endif



} // namespace scudo

compiler-rt/lib/scudo/standalone/wrappers_c_bionic.cpp

+2 −6
Original line number Diff line number Diff line
@@ -55,11 +55,7 @@ scudo::Allocator<scudo::AndroidSvelteConfig, SCUDO_PREFIX(malloc_postinit)> * 
#undef SCUDO_ALLOCATOR

#undef SCUDO_PREFIX



// The following is the only function that will end up initializing both

// allocators, which will result in a slight increase in memory footprint.

INTERFACE void __scudo_print_stats(void) {

  Allocator.printStats();

  SvelteAllocator.printStats();

}

// TODO(kostyak): support both allocators.

INTERFACE void __scudo_print_stats(void) { Allocator.printStats(); }



#endif // SCUDO_ANDROID && _BIONIC