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rocksdb/util/jemalloc_nodump_allocator.cc

126 lines
4.4 KiB

// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
// This source code is licensed under both the GPLv2 (found in the
// COPYING file in the root directory) and Apache 2.0 License
// (found in the LICENSE.Apache file in the root directory).
#include "util/jemalloc_nodump_allocator.h"
#include <string>
#include "util/string_util.h"
namespace rocksdb {
#ifdef ROCKSDB_JEMALLOC_NODUMP_ALLOCATOR
std::atomic<extent_alloc_t*> JemallocNodumpAllocator::original_alloc_{nullptr};
JemallocNodumpAllocator::JemallocNodumpAllocator(
unsigned arena_index, int flags, std::unique_ptr<extent_hooks_t>&& hooks)
: arena_index_(arena_index), flags_(flags), hooks_(std::move(hooks)) {
assert(arena_index != 0);
}
void* JemallocNodumpAllocator::Allocate(size_t size) {
return mallocx(size, flags_);
}
void JemallocNodumpAllocator::Deallocate(void* p) { dallocx(p, flags_); }
void* JemallocNodumpAllocator::Alloc(extent_hooks_t* extent, void* new_addr,
size_t size, size_t alignment, bool* zero,
bool* commit, unsigned arena_ind) {
extent_alloc_t* original_alloc =
original_alloc_.load(std::memory_order_relaxed);
assert(original_alloc != nullptr);
void* result = original_alloc(extent, new_addr, size, alignment, zero, commit,
arena_ind);
if (result != nullptr) {
int ret = madvise(result, size, MADV_DONTDUMP);
if (ret != 0) {
fprintf(
stderr,
"JemallocNodumpAllocator failed to set MADV_DONTDUMP, error code: %d",
ret);
assert(false);
}
}
return result;
}
JemallocNodumpAllocator::~JemallocNodumpAllocator() {
assert(arena_index_ != 0);
std::string key = "arena." + ToString(arena_index_) + ".destroy";
int ret = mallctl(key.c_str(), nullptr, 0, nullptr, 0);
if (ret != 0) {
fprintf(stderr, "Failed to destroy jemalloc arena, error code: %d\n", ret);
}
}
size_t JemallocNodumpAllocator::UsableSize(void* p,
size_t /*allocation_size*/) const {
return malloc_usable_size(static_cast<void*>(p));
}
#endif // ROCKSDB_JEMALLOC_NODUMP_ALLOCATOR
Status NewJemallocNodumpAllocator(
std::shared_ptr<MemoryAllocator>* memory_allocator) {
#ifndef ROCKSDB_JEMALLOC_NODUMP_ALLOCATOR
*memory_allocator = nullptr;
return Status::NotSupported(
"JemallocNodumpAllocator only available with jemalloc version >= 5 "
"and MADV_DONTDUMP is available.");
#else
if (memory_allocator == nullptr) {
return Status::InvalidArgument("memory_allocator must be non-null.");
}
// Create arena.
unsigned arena_index = 0;
size_t arena_index_size = sizeof(arena_index);
int ret =
mallctl("arenas.create", &arena_index, &arena_index_size, nullptr, 0);
if (ret != 0) {
return Status::Incomplete("Failed to create jemalloc arena, error code: " +
ToString(ret));
}
assert(arena_index != 0);
int flags = MALLOCX_ARENA(arena_index) | MALLOCX_TCACHE_NONE;
std::string key = "arena." + ToString(arena_index) + ".extent_hooks";
// Read existing hooks.
extent_hooks_t* hooks;
size_t hooks_size = sizeof(hooks);
ret = mallctl(key.c_str(), &hooks, &hooks_size, nullptr, 0);
if (ret != 0) {
std::string msg =
"Failed to read existing hooks, error code: " + ToString(ret);
return Status::Incomplete("Failed to read existing hooks, error code: " +
ToString(ret));
}
// Store existing alloc.
extent_alloc_t* original_alloc = hooks->alloc;
extent_alloc_t* expected = nullptr;
bool success __attribute__((__unused__)) =
JemallocNodumpAllocator::original_alloc_.compare_exchange_strong(
expected, original_alloc);
assert(success || original_alloc == expected);
// Set the custom hook.
std::unique_ptr<extent_hooks_t> new_hooks(new extent_hooks_t(*hooks));
new_hooks->alloc = &JemallocNodumpAllocator::Alloc;
extent_hooks_t* hooks_ptr = new_hooks.get();
ret = mallctl(key.c_str(), nullptr, nullptr, &hooks_ptr, sizeof(hooks_ptr));
if (ret != 0) {
return Status::Incomplete("Failed to set custom hook, error code: " +
ToString(ret));
}
// Create cache allocator.
memory_allocator->reset(
new JemallocNodumpAllocator(arena_index, flags, std::move(new_hooks)));
return Status::OK();
#endif // ROCKSDB_JEMALLOC_NODUMP_ALLOCATOR
}
} // namespace rocksdb