*/
#include "config.h"
-
#include "ExecutableAllocator.h"
-#include <errno.h>
+#include "JSCInlines.h"
-#if ENABLE(ASSEMBLER) && OS(DARWIN) && CPU(X86_64)
+#if ENABLE(EXECUTABLE_ALLOCATOR_FIXED)
-#include "TCSpinLock.h"
-#include <mach/mach_init.h>
-#include <mach/vm_map.h>
-#include <sys/mman.h>
+#include "CodeProfiling.h"
+#include <errno.h>
#include <unistd.h>
-#include <wtf/AVLTree.h>
+#include <wtf/MetaAllocator.h>
+#include <wtf/PageReservation.h>
#include <wtf/VMTags.h>
-using namespace WTF;
-
-namespace JSC {
-
-#define TWO_GB (2u * 1024u * 1024u * 1024u)
-#define SIXTEEN_MB (16u * 1024u * 1024u)
-
-// FreeListEntry describes a free chunk of memory, stored in the freeList.
-struct FreeListEntry {
- FreeListEntry(void* pointer, size_t size)
- : pointer(pointer)
- , size(size)
- , nextEntry(0)
- , less(0)
- , greater(0)
- , balanceFactor(0)
- {
- }
-
- // All entries of the same size share a single entry
- // in the AVLTree, and are linked together in a linked
- // list, using nextEntry.
- void* pointer;
- size_t size;
- FreeListEntry* nextEntry;
-
- // These fields are used by AVLTree.
- FreeListEntry* less;
- FreeListEntry* greater;
- int balanceFactor;
-};
-
-// Abstractor class for use in AVLTree.
-// Nodes in the AVLTree are of type FreeListEntry, keyed on
-// (and thus sorted by) their size.
-struct AVLTreeAbstractorForFreeList {
- typedef FreeListEntry* handle;
- typedef int32_t size;
- typedef size_t key;
-
- handle get_less(handle h) { return h->less; }
- void set_less(handle h, handle lh) { h->less = lh; }
- handle get_greater(handle h) { return h->greater; }
- void set_greater(handle h, handle gh) { h->greater = gh; }
- int get_balance_factor(handle h) { return h->balanceFactor; }
- void set_balance_factor(handle h, int bf) { h->balanceFactor = bf; }
-
- static handle null() { return 0; }
-
- int compare_key_key(key va, key vb) { return va - vb; }
- int compare_key_node(key k, handle h) { return compare_key_key(k, h->size); }
- int compare_node_node(handle h1, handle h2) { return compare_key_key(h1->size, h2->size); }
-};
-
-// Used to reverse sort an array of FreeListEntry pointers.
-static int reverseSortFreeListEntriesByPointer(const void* leftPtr, const void* rightPtr)
-{
- FreeListEntry* left = *(FreeListEntry**)leftPtr;
- FreeListEntry* right = *(FreeListEntry**)rightPtr;
-
- return (intptr_t)(right->pointer) - (intptr_t)(left->pointer);
-}
-
-// Used to reverse sort an array of pointers.
-static int reverseSortCommonSizedAllocations(const void* leftPtr, const void* rightPtr)
-{
- void* left = *(void**)leftPtr;
- void* right = *(void**)rightPtr;
-
- return (intptr_t)right - (intptr_t)left;
-}
-
-class FixedVMPoolAllocator
-{
- // The free list is stored in a sorted tree.
- typedef AVLTree<AVLTreeAbstractorForFreeList, 40> SizeSortedFreeTree;
-
- // Use madvise as apropriate to prevent freed pages from being spilled,
- // and to attempt to ensure that used memory is reported correctly.
-#if HAVE(MADV_FREE_REUSE)
- void release(void* position, size_t size)
- {
- while (madvise(position, size, MADV_FREE_REUSABLE) == -1 && errno == EAGAIN) { }
- }
+#if OS(DARWIN)
+#include <sys/mman.h>
+#endif
- void reuse(void* position, size_t size)
- {
- while (madvise(position, size, MADV_FREE_REUSE) == -1 && errno == EAGAIN) { }
- }
-#elif HAVE(MADV_DONTNEED)
- void release(void* position, size_t size)
- {
- while (madvise(position, size, MADV_DONTNEED) == -1 && errno == EAGAIN) { }
- }
+#if OS(LINUX)
+#include <stdio.h>
+#endif
- void reuse(void*, size_t) {}
-#else
- void release(void*, size_t) {}
- void reuse(void*, size_t) {}
+#if PLATFORM(MAC) && __MAC_OS_X_VERSION_MIN_REQUIRED < 1090
+// MADV_FREE_REUSABLE does not work for JIT memory on older OSes so use MADV_FREE in that case.
+#define WTF_USE_MADV_FREE_FOR_JIT_MEMORY 1
#endif
- // All addition to the free list should go through this method, rather than
- // calling insert directly, to avoid multiple entries beging added with the
- // same key. All nodes being added should be singletons, they should not
- // already be a part of a chain.
- void addToFreeList(FreeListEntry* entry)
- {
- ASSERT(!entry->nextEntry);
+using namespace WTF;
- if (entry->size == m_commonSize) {
- m_commonSizedAllocations.append(entry->pointer);
- delete entry;
- } else if (FreeListEntry* entryInFreeList = m_freeList.search(entry->size, m_freeList.EQUAL)) {
- // m_freeList already contain an entry for this size - insert this node into the chain.
- entry->nextEntry = entryInFreeList->nextEntry;
- entryInFreeList->nextEntry = entry;
- } else
- m_freeList.insert(entry);
- }
+namespace JSC {
+
+uintptr_t startOfFixedExecutableMemoryPool;
- // We do not attempt to coalesce addition, which may lead to fragmentation;
- // instead we periodically perform a sweep to try to coalesce neigboring
- // entries in m_freeList. Presently this is triggered at the point 16MB
- // of memory has been released.
- void coalesceFreeSpace()
+class FixedVMPoolExecutableAllocator : public MetaAllocator {
+ WTF_MAKE_FAST_ALLOCATED;
+public:
+ FixedVMPoolExecutableAllocator()
+ : MetaAllocator(jitAllocationGranule) // round up all allocations to 32 bytes
{
- Vector<FreeListEntry*> freeListEntries;
- SizeSortedFreeTree::Iterator iter;
- iter.start_iter_least(m_freeList);
-
- // Empty m_freeList into a Vector.
- for (FreeListEntry* entry; (entry = *iter); ++iter) {
- // Each entry in m_freeList might correspond to multiple
- // free chunks of memory (of the same size). Walk the chain
- // (this is likely of couse only be one entry long!) adding
- // each entry to the Vector (at reseting the next in chain
- // pointer to separate each node out).
- FreeListEntry* next;
- do {
- next = entry->nextEntry;
- entry->nextEntry = 0;
- freeListEntries.append(entry);
- } while ((entry = next));
- }
- // All entries are now in the Vector; purge the tree.
- m_freeList.purge();
-
- // Reverse-sort the freeListEntries and m_commonSizedAllocations Vectors.
- // We reverse-sort so that we can logically work forwards through memory,
- // whilst popping items off the end of the Vectors using last() and removeLast().
- qsort(freeListEntries.begin(), freeListEntries.size(), sizeof(FreeListEntry*), reverseSortFreeListEntriesByPointer);
- qsort(m_commonSizedAllocations.begin(), m_commonSizedAllocations.size(), sizeof(void*), reverseSortCommonSizedAllocations);
-
- // The entries from m_commonSizedAllocations that cannot be
- // coalesced into larger chunks will be temporarily stored here.
- Vector<void*> newCommonSizedAllocations;
-
- // Keep processing so long as entries remain in either of the vectors.
- while (freeListEntries.size() || m_commonSizedAllocations.size()) {
- // We're going to try to find a FreeListEntry node that we can coalesce onto.
- FreeListEntry* coalescionEntry = 0;
-
- // Is the lowest addressed chunk of free memory of common-size, or is it in the free list?
- if (m_commonSizedAllocations.size() && (!freeListEntries.size() || (m_commonSizedAllocations.last() < freeListEntries.last()->pointer))) {
- // Pop an item from the m_commonSizedAllocations vector - this is the lowest
- // addressed free chunk. Find out the begin and end addresses of the memory chunk.
- void* begin = m_commonSizedAllocations.last();
- void* end = (void*)((intptr_t)begin + m_commonSize);
- m_commonSizedAllocations.removeLast();
-
- // Try to find another free chunk abutting onto the end of the one we have already found.
- if (freeListEntries.size() && (freeListEntries.last()->pointer == end)) {
- // There is an existing FreeListEntry for the next chunk of memory!
- // we can reuse this. Pop it off the end of m_freeList.
- coalescionEntry = freeListEntries.last();
- freeListEntries.removeLast();
- // Update the existing node to include the common-sized chunk that we also found.
- coalescionEntry->pointer = (void*)((intptr_t)coalescionEntry->pointer - m_commonSize);
- coalescionEntry->size += m_commonSize;
- } else if (m_commonSizedAllocations.size() && (m_commonSizedAllocations.last() == end)) {
- // There is a second common-sized chunk that can be coalesced.
- // Allocate a new node.
- m_commonSizedAllocations.removeLast();
- coalescionEntry = new FreeListEntry(begin, 2 * m_commonSize);
- } else {
- // Nope - this poor little guy is all on his own. :-(
- // Add him into the newCommonSizedAllocations vector for now, we're
- // going to end up adding him back into the m_commonSizedAllocations
- // list when we're done.
- newCommonSizedAllocations.append(begin);
- continue;
- }
- } else {
- ASSERT(freeListEntries.size());
- ASSERT(!m_commonSizedAllocations.size() || (freeListEntries.last()->pointer < m_commonSizedAllocations.last()));
- // The lowest addressed item is from m_freeList; pop it from the Vector.
- coalescionEntry = freeListEntries.last();
- freeListEntries.removeLast();
- }
+ m_reservation = PageReservation::reserveWithGuardPages(fixedExecutableMemoryPoolSize, OSAllocator::JSJITCodePages, EXECUTABLE_POOL_WRITABLE, true);
+ if (m_reservation) {
+ ASSERT(m_reservation.size() == fixedExecutableMemoryPoolSize);
+ addFreshFreeSpace(m_reservation.base(), m_reservation.size());
- // Right, we have a FreeListEntry, we just need check if there is anything else
- // to coalesce onto the end.
- ASSERT(coalescionEntry);
- while (true) {
- // Calculate the end address of the chunk we have found so far.
- void* end = (void*)((intptr_t)coalescionEntry->pointer - coalescionEntry->size);
-
- // Is there another chunk adjacent to the one we already have?
- if (freeListEntries.size() && (freeListEntries.last()->pointer == end)) {
- // Yes - another FreeListEntry -pop it from the list.
- FreeListEntry* coalescee = freeListEntries.last();
- freeListEntries.removeLast();
- // Add it's size onto our existing node.
- coalescionEntry->size += coalescee->size;
- delete coalescee;
- } else if (m_commonSizedAllocations.size() && (m_commonSizedAllocations.last() == end)) {
- // We can coalesce the next common-sized chunk.
- m_commonSizedAllocations.removeLast();
- coalescionEntry->size += m_commonSize;
- } else
- break; // Nope, nothing to be added - stop here.
- }
-
- // We've coalesced everything we can onto the current chunk.
- // Add it back into m_freeList.
- addToFreeList(coalescionEntry);
+ startOfFixedExecutableMemoryPool = reinterpret_cast<uintptr_t>(m_reservation.base());
}
-
- // All chunks of free memory larger than m_commonSize should be
- // back in m_freeList by now. All that remains to be done is to
- // copy the contents on the newCommonSizedAllocations back into
- // the m_commonSizedAllocations Vector.
- ASSERT(m_commonSizedAllocations.size() == 0);
- m_commonSizedAllocations.append(newCommonSizedAllocations);
}
-public:
-
- FixedVMPoolAllocator(size_t commonSize, size_t totalHeapSize)
- : m_commonSize(commonSize)
- , m_countFreedSinceLastCoalesce(0)
- , m_totalHeapSize(totalHeapSize)
+ virtual ~FixedVMPoolExecutableAllocator();
+
+protected:
+ virtual void* allocateNewSpace(size_t&) override
{
- // Cook up an address to allocate at, using the following recipe:
- // 17 bits of zero, stay in userspace kids.
- // 26 bits of randomness for ASLR.
- // 21 bits of zero, at least stay aligned within one level of the pagetables.
- //
- // But! - as a temporary workaround for some plugin problems (rdar://problem/6812854),
- // for now instead of 2^26 bits of ASLR lets stick with 25 bits of randomization plus
- // 2^24, which should put up somewhere in the middle of usespace (in the address range
- // 0x200000000000 .. 0x5fffffffffff).
- intptr_t randomLocation = arc4random() & ((1 << 25) - 1);
- randomLocation += (1 << 24);
- randomLocation <<= 21;
- m_base = mmap(reinterpret_cast<void*>(randomLocation), m_totalHeapSize, INITIAL_PROTECTION_FLAGS, MAP_PRIVATE | MAP_ANON, VM_TAG_FOR_EXECUTABLEALLOCATOR_MEMORY, 0);
- if (!m_base)
- CRASH();
-
- // For simplicity, we keep all memory in m_freeList in a 'released' state.
- // This means that we can simply reuse all memory when allocating, without
- // worrying about it's previous state, and also makes coalescing m_freeList
- // simpler since we need not worry about the possibility of coalescing released
- // chunks with non-released ones.
- release(m_base, m_totalHeapSize);
- m_freeList.insert(new FreeListEntry(m_base, m_totalHeapSize));
+ // We're operating in a fixed pool, so new allocation is always prohibited.
+ return 0;
}
-
- void* alloc(size_t size)
+
+ virtual void notifyNeedPage(void* page) override
{
- void* result;
-
- // Freed allocations of the common size are not stored back into the main
- // m_freeList, but are instead stored in a separate vector. If the request
- // is for a common sized allocation, check this list.
- if ((size == m_commonSize) && m_commonSizedAllocations.size()) {
- result = m_commonSizedAllocations.last();
- m_commonSizedAllocations.removeLast();
- } else {
- // Serach m_freeList for a suitable sized chunk to allocate memory from.
- FreeListEntry* entry = m_freeList.search(size, m_freeList.GREATER_EQUAL);
-
- // This would be bad news.
- if (!entry) {
- // Errk! Lets take a last-ditch desparation attempt at defragmentation...
- coalesceFreeSpace();
- // Did that free up a large enough chunk?
- entry = m_freeList.search(size, m_freeList.GREATER_EQUAL);
- // No?... *BOOM!*
- if (!entry)
- CRASH();
- }
- ASSERT(entry->size != m_commonSize);
-
- // Remove the entry from m_freeList. But! -
- // Each entry in the tree may represent a chain of multiple chunks of the
- // same size, and we only want to remove one on them. So, if this entry
- // does have a chain, just remove the first-but-one item from the chain.
- if (FreeListEntry* next = entry->nextEntry) {
- // We're going to leave 'entry' in the tree; remove 'next' from its chain.
- entry->nextEntry = next->nextEntry;
- next->nextEntry = 0;
- entry = next;
- } else
- m_freeList.remove(entry->size);
-
- // Whoo!, we have a result!
- ASSERT(entry->size >= size);
- result = entry->pointer;
-
- // If the allocation exactly fits the chunk we found in the,
- // m_freeList then the FreeListEntry node is no longer needed.
- if (entry->size == size)
- delete entry;
- else {
- // There is memory left over, and it is not of the common size.
- // We can reuse the existing FreeListEntry node to add this back
- // into m_freeList.
- entry->pointer = (void*)((intptr_t)entry->pointer + size);
- entry->size -= size;
- addToFreeList(entry);
- }
- }
-
- // Call reuse to report to the operating system that this memory is in use.
- ASSERT(isWithinVMPool(result, size));
- reuse(result, size);
- return result;
+#if USE(MADV_FREE_FOR_JIT_MEMORY)
+ UNUSED_PARAM(page);
+#else
+ m_reservation.commit(page, pageSize());
+#endif
}
-
- void free(void* pointer, size_t size)
+
+ virtual void notifyPageIsFree(void* page) override
{
- // Call release to report to the operating system that this
- // memory is no longer in use, and need not be paged out.
- ASSERT(isWithinVMPool(pointer, size));
- release(pointer, size);
-
- // Common-sized allocations are stored in the m_commonSizedAllocations
- // vector; all other freed chunks are added to m_freeList.
- if (size == m_commonSize)
- m_commonSizedAllocations.append(pointer);
- else
- addToFreeList(new FreeListEntry(pointer, size));
-
- // Do some housekeeping. Every time we reach a point that
- // 16MB of allocations have been freed, sweep m_freeList
- // coalescing any neighboring fragments.
- m_countFreedSinceLastCoalesce += size;
- if (m_countFreedSinceLastCoalesce >= SIXTEEN_MB) {
- m_countFreedSinceLastCoalesce = 0;
- coalesceFreeSpace();
+#if USE(MADV_FREE_FOR_JIT_MEMORY)
+ for (;;) {
+ int result = madvise(page, pageSize(), MADV_FREE);
+ if (!result)
+ return;
+ ASSERT(result == -1);
+ if (errno != EAGAIN) {
+ RELEASE_ASSERT_NOT_REACHED(); // In debug mode, this should be a hard failure.
+ break; // In release mode, we should just ignore the error - not returning memory to the OS is better than crashing, especially since we _will_ be able to reuse the memory internally anyway.
+ }
}
+#else
+ m_reservation.decommit(page, pageSize());
+#endif
}
private:
+ PageReservation m_reservation;
+};
-#ifndef NDEBUG
- bool isWithinVMPool(void* pointer, size_t size)
- {
- return pointer >= m_base && (reinterpret_cast<char*>(pointer) + size <= reinterpret_cast<char*>(m_base) + m_totalHeapSize);
- }
-#endif
+static FixedVMPoolExecutableAllocator* allocator;
- // Freed space from the most common sized allocations will be held in this list, ...
- const size_t m_commonSize;
- Vector<void*> m_commonSizedAllocations;
+void ExecutableAllocator::initializeAllocator()
+{
+ ASSERT(!allocator);
+ allocator = new FixedVMPoolExecutableAllocator();
+ CodeProfiling::notifyAllocator(allocator);
+}
- // ... and all other freed allocations are held in m_freeList.
- SizeSortedFreeTree m_freeList;
+ExecutableAllocator::ExecutableAllocator(VM&)
+{
+ ASSERT(allocator);
+}
- // This is used for housekeeping, to trigger defragmentation of the freed lists.
- size_t m_countFreedSinceLastCoalesce;
+ExecutableAllocator::~ExecutableAllocator()
+{
+}
- void* m_base;
- size_t m_totalHeapSize;
-};
+FixedVMPoolExecutableAllocator::~FixedVMPoolExecutableAllocator()
+{
+ m_reservation.deallocate();
+}
-void ExecutableAllocator::intializePageSize()
+bool ExecutableAllocator::isValid() const
{
- ExecutableAllocator::pageSize = getpagesize();
+ return !!allocator->bytesReserved();
}
-static FixedVMPoolAllocator* allocator = 0;
-static SpinLock spinlock = SPINLOCK_INITIALIZER;
+bool ExecutableAllocator::underMemoryPressure()
+{
+ MetaAllocator::Statistics statistics = allocator->currentStatistics();
+ return statistics.bytesAllocated > statistics.bytesReserved / 2;
+}
-ExecutablePool::Allocation ExecutablePool::systemAlloc(size_t size)
+double ExecutableAllocator::memoryPressureMultiplier(size_t addedMemoryUsage)
{
- SpinLockHolder lock_holder(&spinlock);
+ MetaAllocator::Statistics statistics = allocator->currentStatistics();
+ ASSERT(statistics.bytesAllocated <= statistics.bytesReserved);
+ size_t bytesAllocated = statistics.bytesAllocated + addedMemoryUsage;
+ if (bytesAllocated >= statistics.bytesReserved)
+ bytesAllocated = statistics.bytesReserved;
+ double result = 1.0;
+ size_t divisor = statistics.bytesReserved - bytesAllocated;
+ if (divisor)
+ result = static_cast<double>(statistics.bytesReserved) / divisor;
+ if (result < 1.0)
+ result = 1.0;
+ return result;
+}
- if (!allocator)
- allocator = new FixedVMPoolAllocator(JIT_ALLOCATOR_LARGE_ALLOC_SIZE, TWO_GB);
- ExecutablePool::Allocation alloc = {reinterpret_cast<char*>(allocator->alloc(size)), size};
- return alloc;
+PassRefPtr<ExecutableMemoryHandle> ExecutableAllocator::allocate(VM& vm, size_t sizeInBytes, void* ownerUID, JITCompilationEffort effort)
+{
+ RefPtr<ExecutableMemoryHandle> result = allocator->allocate(sizeInBytes, ownerUID);
+ if (!result) {
+ if (effort == JITCompilationCanFail)
+ return result;
+ releaseExecutableMemory(vm);
+ result = allocator->allocate(sizeInBytes, ownerUID);
+ RELEASE_ASSERT(result);
+ }
+ return result.release();
}
-void ExecutablePool::systemRelease(const ExecutablePool::Allocation& allocation)
+size_t ExecutableAllocator::committedByteCount()
{
- SpinLockHolder lock_holder(&spinlock);
+ return allocator->bytesCommitted();
+}
- ASSERT(allocator);
- allocator->free(allocation.pages, allocation.size);
+#if ENABLE(META_ALLOCATOR_PROFILE)
+void ExecutableAllocator::dumpProfile()
+{
+ allocator->dumpProfile();
}
+#endif
}
-#endif // HAVE(ASSEMBLER)
+
+#endif // ENABLE(EXECUTABLE_ALLOCATOR_FIXED)
projects / apple / javascriptcore.git / blobdiff