Author: ChiaHungDuan Date: 2024-09-10T18:55:12-07:00 New Revision: 00b2d78142495605c0c01f9228620a96b5b949d3
URL: https://github.com/llvm/llvm-project/commit/00b2d78142495605c0c01f9228620a96b5b949d3 DIFF: https://github.com/llvm/llvm-project/commit/00b2d78142495605c0c01f9228620a96b5b949d3.diff LOG: Revert "[scudo] Fix the logic of MaxAllowedFragmentedPages (#107927)" This reverts commit 6e854a6a01d310689a8b5d50126decd46b3880ea. Added: Modified: compiler-rt/lib/scudo/standalone/secondary.h Removed: ################################################################################ diff --git a/compiler-rt/lib/scudo/standalone/secondary.h b/compiler-rt/lib/scudo/standalone/secondary.h index c79ec1360b00a7..1a232b9b9fb2d7 100644 --- a/compiler-rt/lib/scudo/standalone/secondary.h +++ b/compiler-rt/lib/scudo/standalone/secondary.h @@ -72,16 +72,13 @@ namespace { struct CachedBlock { static constexpr u16 CacheIndexMax = UINT16_MAX; static constexpr u16 InvalidEntry = CacheIndexMax; - // We allow a certain amount of fragmentation and part of the fragmented bytes - // will be released by `releaseAndZeroPagesToOS()`. This increases the chance - // of cache hit rate and reduces the overhead to the RSS at the same time. See - // more details in the `MapAllocatorCache::retrieve()` section. - // - // We arrived at this default value after noticing that mapping in larger - // memory regions performs better than releasing memory and forcing a cache - // hit. According to the data, it suggests that beyond 4 pages, the release - // execution time is longer than the map execution time. In this way, - // the default is dependent on the platform. + // * MaxReleasedCachePages default is currently 4 + // - We arrived at this value after noticing that mapping + // in larger memory regions performs better than releasing + // memory and forcing a cache hit. According to the data, + // it suggests that beyond 4 pages, the release execution time is + // longer than the map execution time. In this way, the default + // is dependent on the platform. static constexpr uptr MaxReleasedCachePages = 4U; uptr CommitBase = 0; @@ -728,14 +725,8 @@ MapAllocator<Config>::tryAllocateFromCache(const Options &Options, uptr Size, uptr EntryHeaderPos; uptr MaxAllowedFragmentedPages = MaxUnreleasedCachePages; - if (LIKELY(!useMemoryTagging<Config>(Options))) { + if (UNLIKELY(useMemoryTagging<Config>(Options))) MaxAllowedFragmentedPages += CachedBlock::MaxReleasedCachePages; - } else { - // TODO: Enable MaxReleasedCachePages may result in pages for an entry being - // partially released and it erases the tag of those pages as well. To - // support this feature for MTE, we need to tag those pages again. - DCHECK_EQ(CachedBlock::MaxReleasedCachePages, 0U); - } Entry = Cache.retrieve(MaxAllowedFragmentedPages, Size, Alignment, getHeadersSize(), EntryHeaderPos); _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
