[compiler-rt] 5f771c9 - [scudo] Support dumping fragmentation data in SizeClassAllocator64
Chia-hung Duan via llvm-commits
llvm-commits at lists.llvm.org
Mon Aug 21 10:29:35 PDT 2023
Author: Chia-hung Duan
Date: 2023-08-21T17:26:42Z
New Revision: 5f771c9936b828d5fc017ad558e84702500df99c
URL: https://github.com/llvm/llvm-project/commit/5f771c9936b828d5fc017ad558e84702500df99c
DIFF: https://github.com/llvm/llvm-project/commit/5f771c9936b828d5fc017ad558e84702500df99c.diff
LOG: [scudo] Support dumping fragmentation data in SizeClassAllocator64
This tells the number of pages that still have blocks in-used, i.e.,
those pages can't do releaseToOSMaybe(). Along with the information of
getStats() and RSS usage from the system (like smaps), we can tell if
the heuristic in releaseToOSMaybe() works well in certain scenarios.
Here's the sample output:
```
Fragmentation Stats: SizeClassAllocator64: page size = 4096
01 ( 32): inuse/total blocks: 275/ 416 inuse/total pages: 4/ 4 inuse bytes: 16K
02 ( 48): inuse/total blocks: 182/ 312 inuse/total pages: 4/ 4 inuse bytes: 16K
03 ( 64): inuse/total blocks: 169/ 312 inuse/total pages: 5/ 5 inuse bytes: 20K
...
32 ( 1040): inuse/total blocks: 90/ 152 inuse/total pages: 37/ 39 inuse bytes: 148K
33 ( 1168): inuse/total blocks: 136/ 232 inuse/total pages: 64/ 67 inuse bytes: 256K
34 ( 1296): inuse/total blocks: 138/ 226 inuse/total pages: 68/ 72 inuse bytes: 272K
35 ( 1424): inuse/total blocks: 140/ 232 inuse/total pages: 78/ 81 inuse bytes: 312K
36 ( 1552): inuse/total blocks: 157/ 248 inuse/total pages: 89/ 94 inuse bytes: 356K
...
```
SizeClassAllocator32 requires further refactoring to support this.
Reviewed By: cferris
Differential Revision: https://reviews.llvm.org/D158225
Added:
Modified:
compiler-rt/lib/scudo/standalone/combined.h
compiler-rt/lib/scudo/standalone/primary32.h
compiler-rt/lib/scudo/standalone/primary64.h
compiler-rt/lib/scudo/standalone/release.h
compiler-rt/lib/scudo/standalone/tests/combined_test.cpp
compiler-rt/lib/scudo/standalone/tests/primary_test.cpp
compiler-rt/lib/scudo/standalone/wrappers_c.inc
Removed:
################################################################################
diff --git a/compiler-rt/lib/scudo/standalone/combined.h b/compiler-rt/lib/scudo/standalone/combined.h
index b97bcc9fdbc8c7..e1db7a70301184 100644
--- a/compiler-rt/lib/scudo/standalone/combined.h
+++ b/compiler-rt/lib/scudo/standalone/combined.h
@@ -754,6 +754,13 @@ class Allocator {
Str.output();
}
+ void printFragmentationInfo() {
+ ScopedString Str;
+ Primary.getFragmentationInfo(&Str);
+ // Secondary allocator dumps the fragmentation data in getStats().
+ Str.output();
+ }
+
void releaseToOS(ReleaseToOS ReleaseType) {
initThreadMaybe();
if (ReleaseType == ReleaseToOS::ForceAll)
diff --git a/compiler-rt/lib/scudo/standalone/primary32.h b/compiler-rt/lib/scudo/standalone/primary32.h
index d804f416202d12..1fe0d16ba8a7a9 100644
--- a/compiler-rt/lib/scudo/standalone/primary32.h
+++ b/compiler-rt/lib/scudo/standalone/primary32.h
@@ -311,6 +311,12 @@ template <typename Config> class SizeClassAllocator32 {
}
}
+ void getFragmentationInfo(ScopedString *Str) {
+ // TODO(chiahungduan): Organize the steps in releaseToOSMaybe() into
+ // functions which make the collection of fragmentation data easier.
+ Str->append("Fragmentation Stats: SizeClassAllocator32: Unsupported yet\n");
+ }
+
bool setOption(Option O, sptr Value) {
if (O == Option::ReleaseInterval) {
const s32 Interval = Max(Min(static_cast<s32>(Value),
diff --git a/compiler-rt/lib/scudo/standalone/primary64.h b/compiler-rt/lib/scudo/standalone/primary64.h
index 5f2b6c4a8f2b8e..847dbf71eb04eb 100644
--- a/compiler-rt/lib/scudo/standalone/primary64.h
+++ b/compiler-rt/lib/scudo/standalone/primary64.h
@@ -367,6 +367,18 @@ template <typename Config> class SizeClassAllocator64 {
}
}
+ void getFragmentationInfo(ScopedString *Str) {
+ Str->append(
+ "Fragmentation Stats: SizeClassAllocator64: page size = %zu bytes\n",
+ getPageSizeCached());
+
+ for (uptr I = 1; I < NumClasses; I++) {
+ RegionInfo *Region = getRegionInfo(I);
+ ScopedLock L(Region->MMLock);
+ getRegionFragmentationInfo(Region, I, Str);
+ }
+ }
+
bool setOption(Option O, sptr Value) {
if (O == Option::ReleaseInterval) {
const s32 Interval = Max(Min(static_cast<s32>(Value),
@@ -951,10 +963,10 @@ template <typename Config> class SizeClassAllocator64 {
if (Region->MemMapInfo.MappedUser == 0)
return;
const uptr BlockSize = getSizeByClassId(ClassId);
- const uptr InUse =
+ const uptr InUseBlocks =
Region->FreeListInfo.PoppedBlocks - Region->FreeListInfo.PushedBlocks;
const uptr BytesInFreeList =
- Region->MemMapInfo.AllocatedUser - InUse * BlockSize;
+ Region->MemMapInfo.AllocatedUser - InUseBlocks * BlockSize;
uptr RegionPushedBytesDelta = 0;
if (BytesInFreeList >=
Region->ReleaseInfo.BytesInFreeListAtLastCheckpoint) {
@@ -968,13 +980,54 @@ template <typename Config> class SizeClassAllocator64 {
"released: %6zuK latest pushed bytes: %6zuK region: 0x%zx (0x%zx)\n",
Region->Exhausted ? "F" : " ", ClassId, getSizeByClassId(ClassId),
Region->MemMapInfo.MappedUser >> 10, Region->FreeListInfo.PoppedBlocks,
- Region->FreeListInfo.PushedBlocks, InUse, TotalChunks,
+ Region->FreeListInfo.PushedBlocks, InUseBlocks, TotalChunks,
Region->ReleaseInfo.RangesReleased,
Region->ReleaseInfo.LastReleasedBytes >> 10,
RegionPushedBytesDelta >> 10, Region->RegionBeg,
getRegionBaseByClassId(ClassId));
}
+ void getRegionFragmentationInfo(RegionInfo *Region, uptr ClassId,
+ ScopedString *Str) REQUIRES(Region->MMLock) {
+ const uptr BlockSize = getSizeByClassId(ClassId);
+ const uptr AllocatedUserEnd =
+ Region->MemMapInfo.AllocatedUser + Region->RegionBeg;
+
+ SinglyLinkedList<BatchGroup> GroupsToRelease;
+ {
+ ScopedLock L(Region->FLLock);
+ GroupsToRelease = Region->FreeListInfo.BlockList;
+ Region->FreeListInfo.BlockList.clear();
+ }
+
+ FragmentationRecorder Recorder;
+ if (!GroupsToRelease.empty()) {
+ PageReleaseContext Context =
+ markFreeBlocks(Region, BlockSize, AllocatedUserEnd,
+ getCompactPtrBaseByClassId(ClassId), GroupsToRelease);
+ auto SkipRegion = [](UNUSED uptr RegionIndex) { return false; };
+ releaseFreeMemoryToOS(Context, Recorder, SkipRegion);
+
+ mergeGroupsToReleaseBack(Region, GroupsToRelease);
+ }
+
+ ScopedLock L(Region->FLLock);
+ const uptr PageSize = getPageSizeCached();
+ const uptr TotalBlocks = Region->MemMapInfo.AllocatedUser / BlockSize;
+ const uptr InUseBlocks =
+ Region->FreeListInfo.PoppedBlocks - Region->FreeListInfo.PushedBlocks;
+ const uptr AllocatedPagesCount =
+ roundUp(Region->MemMapInfo.AllocatedUser, PageSize) / PageSize;
+ const uptr InUsePages =
+ AllocatedPagesCount - Recorder.getReleasedPagesCount();
+ const uptr InUseBytes = InUsePages * PageSize;
+
+ Str->append(" %02zu (%6zu): inuse/total blocks: %6zu/%6zu inuse/total "
+ "pages: %6zu/%6zu inuse bytes: %6zuK\n",
+ ClassId, BlockSize, InUseBlocks, TotalBlocks, InUsePages,
+ AllocatedPagesCount, InUseBytes >> 10);
+ }
+
NOINLINE uptr releaseToOSMaybe(RegionInfo *Region, uptr ClassId,
ReleaseToOS ReleaseType = ReleaseToOS::Normal)
REQUIRES(Region->MMLock) EXCLUDES(Region->FLLock) {
diff --git a/compiler-rt/lib/scudo/standalone/release.h b/compiler-rt/lib/scudo/standalone/release.h
index 5bf963d0f26fcd..e138570e799333 100644
--- a/compiler-rt/lib/scudo/standalone/release.h
+++ b/compiler-rt/lib/scudo/standalone/release.h
@@ -80,6 +80,21 @@ class ReleaseRecorder {
MapPlatformData *Data = nullptr;
};
+class FragmentationRecorder {
+public:
+ FragmentationRecorder() = default;
+
+ uptr getReleasedPagesCount() const { return ReleasedPagesCount; }
+
+ void releasePageRangeToOS(uptr From, uptr To) {
+ DCHECK_EQ((To - From) % getPageSizeCached(), 0U);
+ ReleasedPagesCount += (To - From) / getPageSizeCached();
+ }
+
+private:
+ uptr ReleasedPagesCount = 0;
+};
+
// A buffer pool which holds a fixed number of static buffers for fast buffer
// allocation. If the request size is greater than `StaticBufferSize`, it'll
// delegate the allocation to map().
diff --git a/compiler-rt/lib/scudo/standalone/tests/combined_test.cpp b/compiler-rt/lib/scudo/standalone/tests/combined_test.cpp
index 79d3278495d704..83135f9bd337db 100644
--- a/compiler-rt/lib/scudo/standalone/tests/combined_test.cpp
+++ b/compiler-rt/lib/scudo/standalone/tests/combined_test.cpp
@@ -170,6 +170,7 @@ void ScudoCombinedTest<Config>::BasicTest(scudo::uptr SizeLog) {
}
Allocator->printStats();
+ Allocator->printFragmentationInfo();
}
#define SCUDO_MAKE_BASIC_TEST(SizeLog) \
diff --git a/compiler-rt/lib/scudo/standalone/tests/primary_test.cpp b/compiler-rt/lib/scudo/standalone/tests/primary_test.cpp
index 6e580e4fef5102..aebd4a998a6e67 100644
--- a/compiler-rt/lib/scudo/standalone/tests/primary_test.cpp
+++ b/compiler-rt/lib/scudo/standalone/tests/primary_test.cpp
@@ -335,6 +335,7 @@ SCUDO_TYPED_TEST(ScudoPrimaryTest, PrimaryThreaded) {
Allocator->releaseToOS(scudo::ReleaseToOS::Force);
scudo::ScopedString Str;
Allocator->getStats(&Str);
+ Allocator->getFragmentationInfo(&Str);
Str.output();
}
diff --git a/compiler-rt/lib/scudo/standalone/wrappers_c.inc b/compiler-rt/lib/scudo/standalone/wrappers_c.inc
index 2c8e382dba0b05..a475927b9f51af 100644
--- a/compiler-rt/lib/scudo/standalone/wrappers_c.inc
+++ b/compiler-rt/lib/scudo/standalone/wrappers_c.inc
@@ -198,6 +198,7 @@ INTERFACE WEAK int SCUDO_PREFIX(mallopt)(int param, int value) {
return 1;
} else if (param == M_LOG_STATS) {
SCUDO_ALLOCATOR.printStats();
+ SCUDO_ALLOCATOR.printFragmentationInfo();
return 1;
} else {
scudo::Option option;
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