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path: root/lib/scudo/scudo_allocator_combined.h
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2017-07-13[scudo] Do not grab a cache for secondary allocation & per related changesKostya Kortchinsky
Summary: Secondary backed allocations do not require a cache. While it's not necessary an issue when each thread has its cache, it becomes one with a shared pool of caches (Android), as a Secondary backed allocation or deallocation holds a cache that could be useful to another thread doing a Primary backed allocation. We introduce an additional PRNG and its mutex (to avoid contention with the Fallback one for Primary allocations) that will provide the `Salt` needed for Secondary backed allocations. I changed some of the code in a way that feels more readable to me (eg: using some values directly rather than going through ternary assigned variables, using directly `true`/`false` rather than `FromPrimary`). I will let reviewers decide if it actually is. An additional change is to mark `CheckForCallocOverflow` as `UNLIKELY`. Reviewers: alekseyshl Reviewed By: alekseyshl Subscribers: llvm-commits Differential Revision: https://reviews.llvm.org/D35358 git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@307958 91177308-0d34-0410-b5e6-96231b3b80d8
2017-06-29[scudo] Change aligned alloc functions to be more compliant & perf changesKostya Kortchinsky
Summary: We were not following the `man` documented behaviors for invalid arguments to `memalign` and associated functions. Using `CHECK` for those was a bit extreme, so we relax the behavior to return null pointers as expected when this happens. Adapt the associated test. I am using this change also to change a few more minor performance improvements: - mark as `UNLIKELY` a bunch of unlikely conditions; - the current `CHECK` in `__sanitizer::RoundUpTo` is redundant for us in *all* calls. So I am introducing our own version without said `CHECK`. - change our combined allocator `GetActuallyAllocatedSize`. We already know if the pointer is from the Primary or Secondary, so the `PointerIsMine` check is redundant as well, and costly for the 32-bit Primary. So we get the size by directly using the available Primary functions. Finally, change a `int` to `uptr` to avoid a warning/error when compiling on Android. Reviewers: alekseyshl Reviewed By: alekseyshl Subscribers: llvm-commits Differential Revision: https://reviews.llvm.org/D34782 git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@306698 91177308-0d34-0410-b5e6-96231b3b80d8
2017-06-20[Sanitizers] Move cached allocator_may_return_null flag to sanitizer_allocatorAlex Shlyapnikov
Summary: Move cached allocator_may_return_null flag to sanitizer_allocator.cc and provide API to consolidate and unify the behavior of all specific allocators. Make all sanitizers using CombinedAllocator to follow AllocatorReturnNullOrDieOnOOM() rules to behave the same way when OOM happens. When OOM happens, turn allocator_out_of_memory flag on regardless of allocator_may_return_null flag value (it used to not to be set when allocator_may_return_null == true). release_to_os_interval_ms and rss_limit_exceeded will likely be moved to sanitizer_allocator.cc too (later). Reviewers: eugenis Subscribers: srhines, kubamracek, llvm-commits Differential Revision: https://reviews.llvm.org/D34310 git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@305858 91177308-0d34-0410-b5e6-96231b3b80d8
2017-05-11[scudo] Use our own combined allocatorKostya Kortchinsky
Summary: The reasoning behind this change is twofold: - the current combined allocator (sanitizer_allocator_combined.h) implements features that are not relevant for Scudo, making some code redundant, and some restrictions not pertinent (alignments for example). This forced us to do some weird things between the frontend and our secondary to make things work; - we have enough information to be able to know if a chunk will be serviced by the Primary or Secondary, allowing us to avoid extraneous calls to functions such as `PointerIsMine` or `CanAllocate`. As a result, the new scudo-specific combined allocator is very straightforward, and allows us to remove some now unnecessary code both in the frontend and the secondary. Unused functions have been left in as unimplemented for now. It turns out to also be a sizeable performance gain (3% faster in some Android memory_replay benchmarks, doing some more on other platforms). Reviewers: alekseyshl, kcc, dvyukov Reviewed By: alekseyshl Subscribers: llvm-commits Differential Revision: https://reviews.llvm.org/D33007 git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@302830 91177308-0d34-0410-b5e6-96231b3b80d8