1243cef245
The existing implementation uses a cache + eviction based scheme to record heap profile information. This design was adopted to ensure a constant memory overhead (due to fixed number of cache entries) along with incremental write-to-disk for evictions. We find that since the number to entries to track is O(unique-allocation-contexts) the overhead of keeping all contexts in memory is not very high. On a clang workload, the max number of unique allocation contexts was ~35K, median ~11K. For each context, we (currently) store 64 bytes of data - this amounts to 5.5MB (max). Given the low overheads for a complex workload, we can simplify the implementation by using a hashmap without eviction. Other changes: * Memory map is dumped at the end rather than startup. The relative order in the profile dump is unchanged since we no longer have evicted entries at runtime. * Added a test to check meminfoblocks are merged. Differential Revision: https://reviews.llvm.org/D111676
36 lines
1.2 KiB
C++
36 lines
1.2 KiB
C++
//===-- memprof_mibmap.cpp -----------------------------------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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// This file is a part of MemProfiler, a memory profiler.
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//
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//===----------------------------------------------------------------------===//
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#include "memprof_mibmap.h"
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#include "sanitizer_common/sanitizer_allocator_internal.h"
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#include "sanitizer_common/sanitizer_mutex.h"
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namespace __memprof {
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void InsertOrMerge(const uptr Id, const MemInfoBlock &Block, MIBMapTy &Map) {
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MIBMapTy::Handle h(&Map, static_cast<uptr>(Id), /*remove=*/false,
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/*create=*/true);
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if (h.created()) {
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LockedMemInfoBlock *lmib =
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(LockedMemInfoBlock *)InternalAlloc(sizeof(LockedMemInfoBlock));
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lmib->mutex.Init();
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lmib->mib = Block;
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*h = lmib;
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} else {
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LockedMemInfoBlock *lmib = *h;
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SpinMutexLock lock(&lmib->mutex);
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lmib->mib.Merge(Block);
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}
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}
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} // namespace __memprof
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