[llvm] r374948 - [JITLink] Switch to slab allocation for InProcessMemoryManager, re-enable test.
Lang Hames via llvm-commits
llvm-commits at lists.llvm.org
Tue Oct 15 14:06:57 PDT 2019
Author: lhames
Date: Tue Oct 15 14:06:57 2019
New Revision: 374948
URL: http://llvm.org/viewvc/llvm-project?rev=374948&view=rev
Log:
[JITLink] Switch to slab allocation for InProcessMemoryManager, re-enable test.
InProcessMemoryManager used to make separate memory allocation calls for each
permission level (RW, RX, RO), which could lead to target-out-of-range errors
if data and code were placed too far apart (this was the source of failures in
the JITLink/AArch64 testcase when it was first landed).
This patch updates InProcessMemoryManager to allocate a single slab which is
subdivided between text and data. This should guarantee that accesses remain
in-range provided that individual object files do not exceed 1Mb in size.
This patch also re-enables the JITLink/AArch64 testcase.
Modified:
llvm/trunk/lib/ExecutionEngine/JITLink/JITLinkMemoryManager.cpp
llvm/trunk/test/ExecutionEngine/JITLink/AArch64/lit.local.cfg
Modified: llvm/trunk/lib/ExecutionEngine/JITLink/JITLinkMemoryManager.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/ExecutionEngine/JITLink/JITLinkMemoryManager.cpp?rev=374948&r1=374947&r2=374948&view=diff
==============================================================================
--- llvm/trunk/lib/ExecutionEngine/JITLink/JITLinkMemoryManager.cpp (original)
+++ llvm/trunk/lib/ExecutionEngine/JITLink/JITLinkMemoryManager.cpp Tue Oct 15 14:06:57 2019
@@ -38,9 +38,21 @@ InProcessMemoryManager::allocate(const S
OnFinalize(applyProtections());
}
Error deallocate() override {
- for (auto &KV : SegBlocks)
- if (auto EC = sys::Memory::releaseMappedMemory(KV.second))
- return errorCodeToError(EC);
+ if (SegBlocks.empty())
+ return Error::success();
+ void *SlabStart = SegBlocks.begin()->second.base();
+ char *SlabEnd = (char *)SlabStart;
+ for (auto &KV : SegBlocks) {
+ SlabStart = std::min(SlabStart, KV.second.base());
+ SlabEnd = std::max(SlabEnd, (char *)(KV.second.base()) +
+ KV.second.allocatedSize());
+ }
+ size_t SlabSize = SlabEnd - (char *)SlabStart;
+ assert((SlabSize % sys::Process::getPageSizeEstimate()) == 0 &&
+ "Slab size is not a multiple of page size");
+ sys::MemoryBlock Slab(SlabStart, SlabSize);
+ if (auto EC = sys::Memory::releaseMappedMemory(Slab))
+ return errorCodeToError(EC);
return Error::success();
}
@@ -70,22 +82,40 @@ InProcessMemoryManager::allocate(const S
static_cast<sys::Memory::ProtectionFlags>(sys::Memory::MF_READ |
sys::Memory::MF_WRITE);
+ // Compute the total number of pages to allocate.
+ size_t TotalSize = 0;
for (auto &KV : Request) {
- auto &Seg = KV.second;
+ const auto &Seg = KV.second;
if (Seg.getAlignment() > sys::Process::getPageSizeEstimate())
return make_error<StringError>("Cannot request higher than page "
"alignment",
inconvertibleErrorCode());
- uint64_t SegmentSize = Seg.getContentSize() + Seg.getZeroFillSize();
+ TotalSize = alignTo(TotalSize, sys::Process::getPageSizeEstimate());
+ TotalSize += Seg.getContentSize();
+ TotalSize += Seg.getZeroFillSize();
+ }
+
+ // Allocate one slab to cover all the segments.
+ std::error_code EC;
+ auto SlabRemaining =
+ sys::Memory::allocateMappedMemory(TotalSize, nullptr, ReadWrite, EC);
+
+ if (EC)
+ return errorCodeToError(EC);
+
+ // Allocate segment memory from the slab.
+ for (auto &KV : Request) {
+
+ const auto &Seg = KV.second;
- std::error_code EC;
- auto SegMem =
- sys::Memory::allocateMappedMemory(SegmentSize, nullptr, ReadWrite, EC);
+ uint64_t SegmentSize = alignTo(Seg.getContentSize() + Seg.getZeroFillSize(),
+ sys::Process::getPageSizeEstimate());
- if (EC)
- return errorCodeToError(EC);
+ sys::MemoryBlock SegMem(SlabRemaining.base(), SegmentSize);
+ SlabRemaining = sys::MemoryBlock((char *)SlabRemaining.base() + SegmentSize,
+ SegmentSize);
// Zero out the zero-fill memory.
memset(static_cast<char *>(SegMem.base()) + Seg.getContentSize(), 0,
Modified: llvm/trunk/test/ExecutionEngine/JITLink/AArch64/lit.local.cfg
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/ExecutionEngine/JITLink/AArch64/lit.local.cfg?rev=374948&r1=374947&r2=374948&view=diff
==============================================================================
--- llvm/trunk/test/ExecutionEngine/JITLink/AArch64/lit.local.cfg (original)
+++ llvm/trunk/test/ExecutionEngine/JITLink/AArch64/lit.local.cfg Tue Oct 15 14:06:57 2019
@@ -1,2 +1,2 @@
-# if not 'AArch64' in config.root.targets:
-config.unsupported = True
+if not 'AArch64' in config.root.targets:
+ config.unsupported = True
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