Race deduplication code proved to be a performance bottleneck in the past if suppressions/annotations are used, or just some races left unaddressed. And we still get user complaints about this:
https://groups.google.com/forum/#!topic/thread-sanitizer/hB0WyiTI4e4
ReportRace already has several layers of caching for racy pcs/addresses to make deduplication faster. However, ReportRace still takes a global mutex (ThreadRegistry and ReportMutex) during deduplication and also calls mmap/munmap (which take process-wide semaphore in kernel), this makes deduplication non-scalable.
This patch moves race deduplication outside of global mutexes and also removes all mmap/munmap calls.
As the result, race_stress.cc with 100 threads and 10000 iterations become 30x faster:
before:
real 0m21.673s
user 0m5.932s
sys 0m34.885s
after:
real 0m0.720s
user 0m23.646s
sys 0m1.254s
http://reviews.llvm.org/D12554
llvm-svn: 246758
Summary:
This change removes `__tsan::StackTrace` class. There are
now three alternatives:
# Lightweight `__sanitizer::StackTrace`, which doesn't own a buffer
of PCs. It is used in functions that need stack traces in read-only
mode, and helps to prevent unnecessary allocations/copies (e.g.
for StackTraces fetched from StackDepot).
# `__sanitizer::BufferedStackTrace`, which stores buffer of PCs in
a constant array. It is used in TraceHeader (non-Go version)
# `__tsan::VarSizeStackTrace`, which owns buffer of PCs, dynamically
allocated via TSan internal allocator.
Test Plan: compiler-rt test suite
Reviewers: dvyukov, kcc
Reviewed By: kcc
Subscribers: llvm-commits, kcc
Differential Revision: http://reviews.llvm.org/D6004
llvm-svn: 221194
The new storage (MetaMap) is based on direct shadow (instead of a hashmap + per-block lists).
This solves a number of problems:
- eliminates quadratic behaviour in SyncTab::GetAndLock (https://code.google.com/p/thread-sanitizer/issues/detail?id=26)
- eliminates contention in SyncTab
- eliminates contention in internal allocator during allocation of sync objects
- removes a bunch of ad-hoc code in java interface
- reduces java shadow from 2x to 1/2x
- allows to memorize heap block meta info for Java and Go
- allows to cleanup sync object meta info for Go
- which in turn enabled deadlock detector for Go
llvm-svn: 209810
This reverts commit r201910.
While __func__ may be standard in C++11, it was only recently added to
MSVC in 2013 CTP, and LLVM supports MSVC 2012. __FUNCTION__ may not be
standard, but it's *very* portable.
llvm-svn: 201916
This is intended to address the following problem.
Episodically we see CHECK-failures when recursive interceptors call back into user code. Effectively we are not "in_rtl" at this point, but it's very complicated and fragile to properly maintain in_rtl property. Instead get rid of it. It was used mostly for sanity CHECKs, which basically never uncover real problems.
Instead introduce ignore_interceptors flag, which is used in very few narrow places to disable recursive interceptors (e.g. during runtime initialization).
llvm-svn: 197979
The annotations are AnnotateIgnoreSyncBegin/End,
may be useful to ignore some infrastructure synchronization
that introduces lots of false negatives.
llvm-svn: 192355
Before, we had an unused internal_getpid function for Linux, and a
platform-independent GetPid function. To make the naming conventions
consistent for syscall-like functions, the GetPid syscall wrapper
in sanitizer_posix.cc is moved to sanitizer_mac.cc, and GetPid is
renamed to internal_getpid, bringing the Linux variant into use.
llvm-svn: 182132
Algorithm description: http://code.google.com/p/thread-sanitizer/wiki/ThreadSanitizerAlgorithm
Status:
The tool is known to work on large real-life applications, but still has quite a few rough edges.
Nothing is guaranteed yet.
The tool works on x86_64 Linux.
Support for 64-bit MacOS 10.7+ is planned for late 2012.
Support for 32-bit OSes is doable, but problematic and not yet planed.
Further commits coming:
- tests
- makefiles
- documentation
- clang driver patch
The code was previously developed at http://code.google.com/p/data-race-test/source/browse/trunk/v2/
by Dmitry Vyukov and Kostya Serebryany with contributions from
Timur Iskhodzhanov, Alexander Potapenko, Alexey Samsonov and Evgeniy Stepanov.
llvm-svn: 156542
Dmitry Vyukov