diff options
Diffstat (limited to '')
| -rw-r--r-- | deps/jemalloc/ChangeLog | 1618 |
1 files changed, 1618 insertions, 0 deletions
diff --git a/deps/jemalloc/ChangeLog b/deps/jemalloc/ChangeLog new file mode 100644 index 0000000..32fde56 --- /dev/null +++ b/deps/jemalloc/ChangeLog @@ -0,0 +1,1618 @@ +Following are change highlights associated with official releases. Important +bug fixes are all mentioned, but some internal enhancements are omitted here for +brevity. Much more detail can be found in the git revision history: + + https://github.com/jemalloc/jemalloc + +* 5.3.0 (May 6, 2022) + + This release contains many speed and space optimizations, from micro + optimizations on common paths to rework of internal data structures and + locking schemes, and many more too detailed to list below. Multiple percent + of system level metric improvements were measured in tested production + workloads. The release has gone through large-scale production testing. + + New features: + - Add the thread.idle mallctl which hints that the calling thread will be + idle for a nontrivial period of time. (@davidtgoldblatt) + - Allow small size classes to be the maximum size class to cache in the + thread-specific cache, through the opt.[lg_]tcache_max option. (@interwq, + @jordalgo) + - Make the behavior of realloc(ptr, 0) configurable with opt.zero_realloc. + (@davidtgoldblatt) + - Add 'make uninstall' support. (@sangshuduo, @Lapenkov) + - Support C++17 over-aligned allocation. (@marksantaniello) + - Add the thread.peak mallctl for approximate per-thread peak memory tracking. + (@davidtgoldblatt) + - Add interval-based stats output opt.stats_interval. (@interwq) + - Add prof.prefix to override filename prefixes for dumps. (@zhxchen17) + - Add high resolution timestamp support for profiling. (@tyroguru) + - Add the --collapsed flag to jeprof for flamegraph generation. + (@igorwwwwwwwwwwwwwwwwwwww) + - Add the --debug-syms-by-id option to jeprof for debug symbols discovery. + (@DeannaGelbart) + - Add the opt.prof_leak_error option to exit with error code when leak is + detected using opt.prof_final. (@yunxuo) + - Add opt.cache_oblivious as an runtime alternative to config.cache_oblivious. + (@interwq) + - Add mallctl interfaces: + + opt.zero_realloc (@davidtgoldblatt) + + opt.cache_oblivious (@interwq) + + opt.prof_leak_error (@yunxuo) + + opt.stats_interval (@interwq) + + opt.stats_interval_opts (@interwq) + + opt.tcache_max (@interwq) + + opt.trust_madvise (@azat) + + prof.prefix (@zhxchen17) + + stats.zero_reallocs (@davidtgoldblatt) + + thread.idle (@davidtgoldblatt) + + thread.peak.{read,reset} (@davidtgoldblatt) + + Bug fixes: + - Fix the synchronization around explicit tcache creation which could cause + invalid tcache identifiers. This regression was first released in 5.0.0. + (@yoshinorim, @davidtgoldblatt) + - Fix a profiling biasing issue which could cause incorrect heap usage and + object counts. This issue existed in all previous releases with the heap + profiling feature. (@davidtgoldblatt) + - Fix the order of stats counter updating on large realloc which could cause + failed assertions. This regression was first released in 5.0.0. (@azat) + - Fix the locking on the arena destroy mallctl, which could cause concurrent + arena creations to fail. This functionality was first introduced in 5.0.0. + (@interwq) + + Portability improvements: + - Remove nothrow from system function declarations on macOS and FreeBSD. + (@davidtgoldblatt, @fredemmott, @leres) + - Improve overcommit and page alignment settings on NetBSD. (@zoulasc) + - Improve CPU affinity support on BSD platforms. (@devnexen) + - Improve utrace detection and support. (@devnexen) + - Improve QEMU support with MADV_DONTNEED zeroed pages detection. (@azat) + - Add memcntl support on Solaris / illumos. (@devnexen) + - Improve CPU_SPINWAIT on ARM. (@AWSjswinney) + - Improve TSD cleanup on FreeBSD. (@Lapenkov) + - Disable percpu_arena if the CPU count cannot be reliably detected. (@azat) + - Add malloc_size(3) override support. (@devnexen) + - Add mmap VM_MAKE_TAG support. (@devnexen) + - Add support for MADV_[NO]CORE. (@devnexen) + - Add support for DragonFlyBSD. (@devnexen) + - Fix the QUANTUM setting on MIPS64. (@brooksdavis) + - Add the QUANTUM setting for ARC. (@vineetgarc) + - Add the QUANTUM setting for LoongArch. (@wangjl-uos) + - Add QNX support. (@jqian-aurora) + - Avoid atexit(3) calls unless the relevant profiling features are enabled. + (@BusyJay, @laiwei-rice, @interwq) + - Fix unknown option detection when using Clang. (@Lapenkov) + - Fix symbol conflict with musl libc. (@georgthegreat) + - Add -Wimplicit-fallthrough checks. (@nickdesaulniers) + - Add __forceinline support on MSVC. (@santagada) + - Improve FreeBSD and Windows CI support. (@Lapenkov) + - Add CI support for PPC64LE architecture. (@ezeeyahoo) + + Incompatible changes: + - Maximum size class allowed in tcache (opt.[lg_]tcache_max) now has an upper + bound of 8MiB. (@interwq) + + Optimizations and refactors (@davidtgoldblatt, @Lapenkov, @interwq): + - Optimize the common cases of the thread cache operations. + - Optimize internal data structures, including RB tree and pairing heap. + - Optimize the internal locking on extent management. + - Extract and refactor the internal page allocator and interface modules. + + Documentation: + - Fix doc build with --with-install-suffix. (@lawmurray, @interwq) + - Add PROFILING_INTERNALS.md. (@davidtgoldblatt) + - Ensure the proper order of doc building and installation. (@Mingli-Yu) + +* 5.2.1 (August 5, 2019) + + This release is primarily about Windows. A critical virtual memory leak is + resolved on all Windows platforms. The regression was present in all releases + since 5.0.0. + + Bug fixes: + - Fix a severe virtual memory leak on Windows. This regression was first + released in 5.0.0. (@Ignition, @j0t, @frederik-h, @davidtgoldblatt, + @interwq) + - Fix size 0 handling in posix_memalign(). This regression was first released + in 5.2.0. (@interwq) + - Fix the prof_log unit test which may observe unexpected backtraces from + compiler optimizations. The test was first added in 5.2.0. (@marxin, + @gnzlbg, @interwq) + - Fix the declaration of the extent_avail tree. This regression was first + released in 5.1.0. (@zoulasc) + - Fix an incorrect reference in jeprof. This functionality was first released + in 3.0.0. (@prehistoric-penguin) + - Fix an assertion on the deallocation fast-path. This regression was first + released in 5.2.0. (@yinan1048576) + - Fix the TLS_MODEL attribute in headers. This regression was first released + in 5.0.0. (@zoulasc, @interwq) + + Optimizations and refactors: + - Implement opt.retain on Windows and enable by default on 64-bit. (@interwq, + @davidtgoldblatt) + - Optimize away a branch on the operator delete[] path. (@mgrice) + - Add format annotation to the format generator function. (@zoulasc) + - Refactor and improve the size class header generation. (@yinan1048576) + - Remove best fit. (@djwatson) + - Avoid blocking on background thread locks for stats. (@oranagra, @interwq) + +* 5.2.0 (April 2, 2019) + + This release includes a few notable improvements, which are summarized below: + 1) improved fast-path performance from the optimizations by @djwatson; 2) + reduced virtual memory fragmentation and metadata usage; and 3) bug fixes on + setting the number of background threads. In addition, peak / spike memory + usage is improved with certain allocation patterns. As usual, the release and + prior dev versions have gone through large-scale production testing. + + New features: + - Implement oversize_threshold, which uses a dedicated arena for allocations + crossing the specified threshold to reduce fragmentation. (@interwq) + - Add extents usage information to stats. (@tyleretzel) + - Log time information for sampled allocations. (@tyleretzel) + - Support 0 size in sdallocx. (@djwatson) + - Output rate for certain counters in malloc_stats. (@zinoale) + - Add configure option --enable-readlinkat, which allows the use of readlinkat + over readlink. (@davidtgoldblatt) + - Add configure options --{enable,disable}-{static,shared} to allow not + building unwanted libraries. (@Ericson2314) + - Add configure option --disable-libdl to enable fully static builds. + (@interwq) + - Add mallctl interfaces: + + opt.oversize_threshold (@interwq) + + stats.arenas.<i>.extent_avail (@tyleretzel) + + stats.arenas.<i>.extents.<j>.n{dirty,muzzy,retained} (@tyleretzel) + + stats.arenas.<i>.extents.<j>.{dirty,muzzy,retained}_bytes + (@tyleretzel) + + Portability improvements: + - Update MSVC builds. (@maksqwe, @rustyx) + - Workaround a compiler optimizer bug on s390x. (@rkmisra) + - Make use of pthread_set_name_np(3) on FreeBSD. (@trasz) + - Implement malloc_getcpu() to enable percpu_arena for windows. (@santagada) + - Link against -pthread instead of -lpthread. (@paravoid) + - Make background_thread not dependent on libdl. (@interwq) + - Add stringify to fix a linker directive issue on MSVC. (@daverigby) + - Detect and fall back when 8-bit atomics are unavailable. (@interwq) + - Fall back to the default pthread_create if dlsym(3) fails. (@interwq) + + Optimizations and refactors: + - Refactor the TSD module. (@davidtgoldblatt) + - Avoid taking extents_muzzy mutex when muzzy is disabled. (@interwq) + - Avoid taking large_mtx for auto arenas on the tcache flush path. (@interwq) + - Optimize ixalloc by avoiding a size lookup. (@interwq) + - Implement opt.oversize_threshold which uses a dedicated arena for requests + crossing the threshold, also eagerly purges the oversize extents. Default + the threshold to 8 MiB. (@interwq) + - Clean compilation with -Wextra. (@gnzlbg, @jasone) + - Refactor the size class module. (@davidtgoldblatt) + - Refactor the stats emitter. (@tyleretzel) + - Optimize pow2_ceil. (@rkmisra) + - Avoid runtime detection of lazy purging on FreeBSD. (@trasz) + - Optimize mmap(2) alignment handling on FreeBSD. (@trasz) + - Improve error handling for THP state initialization. (@jsteemann) + - Rework the malloc() fast path. (@djwatson) + - Rework the free() fast path. (@djwatson) + - Refactor and optimize the tcache fill / flush paths. (@djwatson) + - Optimize sync / lwsync on PowerPC. (@chmeeedalf) + - Bypass extent_dalloc() when retain is enabled. (@interwq) + - Optimize the locking on large deallocation. (@interwq) + - Reduce the number of pages committed from sanity checking in debug build. + (@trasz, @interwq) + - Deprecate OSSpinLock. (@interwq) + - Lower the default number of background threads to 4 (when the feature + is enabled). (@interwq) + - Optimize the trylock spin wait. (@djwatson) + - Use arena index for arena-matching checks. (@interwq) + - Avoid forced decay on thread termination when using background threads. + (@interwq) + - Disable muzzy decay by default. (@djwatson, @interwq) + - Only initialize libgcc unwinder when profiling is enabled. (@paravoid, + @interwq) + + Bug fixes (all only relevant to jemalloc 5.x): + - Fix background thread index issues with max_background_threads. (@djwatson, + @interwq) + - Fix stats output for opt.lg_extent_max_active_fit. (@interwq) + - Fix opt.prof_prefix initialization. (@davidtgoldblatt) + - Properly trigger decay on tcache destroy. (@interwq, @amosbird) + - Fix tcache.flush. (@interwq) + - Detect whether explicit extent zero out is necessary with huge pages or + custom extent hooks, which may change the purge semantics. (@interwq) + - Fix a side effect caused by extent_max_active_fit combined with decay-based + purging, where freed extents can accumulate and not be reused for an + extended period of time. (@interwq, @mpghf) + - Fix a missing unlock on extent register error handling. (@zoulasc) + + Testing: + - Simplify the Travis script output. (@gnzlbg) + - Update the test scripts for FreeBSD. (@devnexen) + - Add unit tests for the producer-consumer pattern. (@interwq) + - Add Cirrus-CI config for FreeBSD builds. (@jasone) + - Add size-matching sanity checks on tcache flush. (@davidtgoldblatt, + @interwq) + + Incompatible changes: + - Remove --with-lg-page-sizes. (@davidtgoldblatt) + + Documentation: + - Attempt to build docs by default, however skip doc building when xsltproc + is missing. (@interwq, @cmuellner) + +* 5.1.0 (May 4, 2018) + + This release is primarily about fine-tuning, ranging from several new features + to numerous notable performance and portability enhancements. The release and + prior dev versions have been running in multiple large scale applications for + months, and the cumulative improvements are substantial in many cases. + + Given the long and successful production runs, this release is likely a good + candidate for applications to upgrade, from both jemalloc 5.0 and before. For + performance-critical applications, the newly added TUNING.md provides + guidelines on jemalloc tuning. + + New features: + - Implement transparent huge page support for internal metadata. (@interwq) + - Add opt.thp to allow enabling / disabling transparent huge pages for all + mappings. (@interwq) + - Add maximum background thread count option. (@djwatson) + - Allow prof_active to control opt.lg_prof_interval and prof.gdump. + (@interwq) + - Allow arena index lookup based on allocation addresses via mallctl. + (@lionkov) + - Allow disabling initial-exec TLS model. (@davidtgoldblatt, @KenMacD) + - Add opt.lg_extent_max_active_fit to set the max ratio between the size of + the active extent selected (to split off from) and the size of the requested + allocation. (@interwq, @davidtgoldblatt) + - Add retain_grow_limit to set the max size when growing virtual address + space. (@interwq) + - Add mallctl interfaces: + + arena.<i>.retain_grow_limit (@interwq) + + arenas.lookup (@lionkov) + + max_background_threads (@djwatson) + + opt.lg_extent_max_active_fit (@interwq) + + opt.max_background_threads (@djwatson) + + opt.metadata_thp (@interwq) + + opt.thp (@interwq) + + stats.metadata_thp (@interwq) + + Portability improvements: + - Support GNU/kFreeBSD configuration. (@paravoid) + - Support m68k, nios2 and SH3 architectures. (@paravoid) + - Fall back to FD_CLOEXEC when O_CLOEXEC is unavailable. (@zonyitoo) + - Fix symbol listing for cross-compiling. (@tamird) + - Fix high bits computation on ARM. (@davidtgoldblatt, @paravoid) + - Disable the CPU_SPINWAIT macro for Power. (@davidtgoldblatt, @marxin) + - Fix MSVC 2015 & 2017 builds. (@rustyx) + - Improve RISC-V support. (@EdSchouten) + - Set name mangling script in strict mode. (@nicolov) + - Avoid MADV_HUGEPAGE on ARM. (@marxin) + - Modify configure to determine return value of strerror_r. + (@davidtgoldblatt, @cferris1000) + - Make sure CXXFLAGS is tested with CPP compiler. (@nehaljwani) + - Fix 32-bit build on MSVC. (@rustyx) + - Fix external symbol on MSVC. (@maksqwe) + - Avoid a printf format specifier warning. (@jasone) + - Add configure option --disable-initial-exec-tls which can allow jemalloc to + be dynamically loaded after program startup. (@davidtgoldblatt, @KenMacD) + - AArch64: Add ILP32 support. (@cmuellner) + - Add --with-lg-vaddr configure option to support cross compiling. + (@cmuellner, @davidtgoldblatt) + + Optimizations and refactors: + - Improve active extent fit with extent_max_active_fit. This considerably + reduces fragmentation over time and improves virtual memory and metadata + usage. (@davidtgoldblatt, @interwq) + - Eagerly coalesce large extents to reduce fragmentation. (@interwq) + - sdallocx: only read size info when page aligned (i.e. possibly sampled), + which speeds up the sized deallocation path significantly. (@interwq) + - Avoid attempting new mappings for in place expansion with retain, since + it rarely succeeds in practice and causes high overhead. (@interwq) + - Refactor OOM handling in newImpl. (@wqfish) + - Add internal fine-grained logging functionality for debugging use. + (@davidtgoldblatt) + - Refactor arena / tcache interactions. (@davidtgoldblatt) + - Refactor extent management with dumpable flag. (@davidtgoldblatt) + - Add runtime detection of lazy purging. (@interwq) + - Use pairing heap instead of red-black tree for extents_avail. (@djwatson) + - Use sysctl on startup in FreeBSD. (@trasz) + - Use thread local prng state instead of atomic. (@djwatson) + - Make decay to always purge one more extent than before, because in + practice large extents are usually the ones that cross the decay threshold. + Purging the additional extent helps save memory as well as reduce VM + fragmentation. (@interwq) + - Fast division by dynamic values. (@davidtgoldblatt) + - Improve the fit for aligned allocation. (@interwq, @edwinsmith) + - Refactor extent_t bitpacking. (@rkmisra) + - Optimize the generated assembly for ticker operations. (@davidtgoldblatt) + - Convert stats printing to use a structured text emitter. (@davidtgoldblatt) + - Remove preserve_lru feature for extents management. (@djwatson) + - Consolidate two memory loads into one on the fast deallocation path. + (@davidtgoldblatt, @interwq) + + Bug fixes (most of the issues are only relevant to jemalloc 5.0): + - Fix deadlock with multithreaded fork in OS X. (@davidtgoldblatt) + - Validate returned file descriptor before use. (@zonyitoo) + - Fix a few background thread initialization and shutdown issues. (@interwq) + - Fix an extent coalesce + decay race by taking both coalescing extents off + the LRU list. (@interwq) + - Fix potentially unbound increase during decay, caused by one thread keep + stashing memory to purge while other threads generating new pages. The + number of pages to purge is checked to prevent this. (@interwq) + - Fix a FreeBSD bootstrap assertion. (@strejda, @interwq) + - Handle 32 bit mutex counters. (@rkmisra) + - Fix a indexing bug when creating background threads. (@davidtgoldblatt, + @binliu19) + - Fix arguments passed to extent_init. (@yuleniwo, @interwq) + - Fix addresses used for ordering mutexes. (@rkmisra) + - Fix abort_conf processing during bootstrap. (@interwq) + - Fix include path order for out-of-tree builds. (@cmuellner) + + Incompatible changes: + - Remove --disable-thp. (@interwq) + - Remove mallctl interfaces: + + config.thp (@interwq) + + Documentation: + - Add TUNING.md. (@interwq, @davidtgoldblatt, @djwatson) + +* 5.0.1 (July 1, 2017) + + This bugfix release fixes several issues, most of which are obscure enough + that typical applications are not impacted. + + Bug fixes: + - Update decay->nunpurged before purging, in order to avoid potential update + races and subsequent incorrect purging volume. (@interwq) + - Only abort on dlsym(3) error if the failure impacts an enabled feature (lazy + locking and/or background threads). This mitigates an initialization + failure bug for which we still do not have a clear reproduction test case. + (@interwq) + - Modify tsd management so that it neither crashes nor leaks if a thread's + only allocation activity is to call free() after TLS destructors have been + executed. This behavior was observed when operating with GNU libc, and is + unlikely to be an issue with other libc implementations. (@interwq) + - Mask signals during background thread creation. This prevents signals from + being inadvertently delivered to background threads. (@jasone, + @davidtgoldblatt, @interwq) + - Avoid inactivity checks within background threads, in order to prevent + recursive mutex acquisition. (@interwq) + - Fix extent_grow_retained() to use the specified hooks when the + arena.<i>.extent_hooks mallctl is used to override the default hooks. + (@interwq) + - Add missing reentrancy support for custom extent hooks which allocate. + (@interwq) + - Post-fork(2), re-initialize the list of tcaches associated with each arena + to contain no tcaches except the forking thread's. (@interwq) + - Add missing post-fork(2) mutex reinitialization for extent_grow_mtx. This + fixes potential deadlocks after fork(2). (@interwq) + - Enforce minimum autoconf version (currently 2.68), since 2.63 is known to + generate corrupt configure scripts. (@jasone) + - Ensure that the configured page size (--with-lg-page) is no larger than the + configured huge page size (--with-lg-hugepage). (@jasone) + +* 5.0.0 (June 13, 2017) + + Unlike all previous jemalloc releases, this release does not use naturally + aligned "chunks" for virtual memory management, and instead uses page-aligned + "extents". This change has few externally visible effects, but the internal + impacts are... extensive. Many other internal changes combine to make this + the most cohesively designed version of jemalloc so far, with ample + opportunity for further enhancements. + + Continuous integration is now an integral aspect of development thanks to the + efforts of @davidtgoldblatt, and the dev branch tends to remain reasonably + stable on the tested platforms (Linux, FreeBSD, macOS, and Windows). As a + side effect the official release frequency may decrease over time. + + New features: + - Implement optional per-CPU arena support; threads choose which arena to use + based on current CPU rather than on fixed thread-->arena associations. + (@interwq) + - Implement two-phase decay of unused dirty pages. Pages transition from + dirty-->muzzy-->clean, where the first phase transition relies on + madvise(... MADV_FREE) semantics, and the second phase transition discards + pages such that they are replaced with demand-zeroed pages on next access. + (@jasone) + - Increase decay time resolution from seconds to milliseconds. (@jasone) + - Implement opt-in per CPU background threads, and use them for asynchronous + decay-driven unused dirty page purging. (@interwq) + - Add mutex profiling, which collects a variety of statistics useful for + diagnosing overhead/contention issues. (@interwq) + - Add C++ new/delete operator bindings. (@djwatson) + - Support manually created arena destruction, such that all data and metadata + are discarded. Add MALLCTL_ARENAS_DESTROYED for accessing merged stats + associated with destroyed arenas. (@jasone) + - Add MALLCTL_ARENAS_ALL as a fixed index for use in accessing + merged/destroyed arena statistics via mallctl. (@jasone) + - Add opt.abort_conf to optionally abort if invalid configuration options are + detected during initialization. (@interwq) + - Add opt.stats_print_opts, so that e.g. JSON output can be selected for the + stats dumped during exit if opt.stats_print is true. (@jasone) + - Add --with-version=VERSION for use when embedding jemalloc into another + project's git repository. (@jasone) + - Add --disable-thp to support cross compiling. (@jasone) + - Add --with-lg-hugepage to support cross compiling. (@jasone) + - Add mallctl interfaces (various authors): + + background_thread + + opt.abort_conf + + opt.retain + + opt.percpu_arena + + opt.background_thread + + opt.{dirty,muzzy}_decay_ms + + opt.stats_print_opts + + arena.<i>.initialized + + arena.<i>.destroy + + arena.<i>.{dirty,muzzy}_decay_ms + + arena.<i>.extent_hooks + + arenas.{dirty,muzzy}_decay_ms + + arenas.bin.<i>.slab_size + + arenas.nlextents + + arenas.lextent.<i>.size + + arenas.create + + stats.background_thread.{num_threads,num_runs,run_interval} + + stats.mutexes.{ctl,background_thread,prof,reset}. + {num_ops,num_spin_acq,num_wait,max_wait_time,total_wait_time,max_num_thds, + num_owner_switch} + + stats.arenas.<i>.{dirty,muzzy}_decay_ms + + stats.arenas.<i>.uptime + + stats.arenas.<i>.{pmuzzy,base,internal,resident} + + stats.arenas.<i>.{dirty,muzzy}_{npurge,nmadvise,purged} + + stats.arenas.<i>.bins.<j>.{nslabs,reslabs,curslabs} + + stats.arenas.<i>.bins.<j>.mutex. + {num_ops,num_spin_acq,num_wait,max_wait_time,total_wait_time,max_num_thds, + num_owner_switch} + + stats.arenas.<i>.lextents.<j>.{nmalloc,ndalloc,nrequests,curlextents} + + stats.arenas.i.mutexes.{large,extent_avail,extents_dirty,extents_muzzy, + extents_retained,decay_dirty,decay_muzzy,base,tcache_list}. + {num_ops,num_spin_acq,num_wait,max_wait_time,total_wait_time,max_num_thds, + num_owner_switch} + + Portability improvements: + - Improve reentrant allocation support, such that deadlock is less likely if + e.g. a system library call in turn allocates memory. (@davidtgoldblatt, + @interwq) + - Support static linking of jemalloc with glibc. (@djwatson) + + Optimizations and refactors: + - Organize virtual memory as "extents" of virtual memory pages, rather than as + naturally aligned "chunks", and store all metadata in arbitrarily distant + locations. This reduces virtual memory external fragmentation, and will + interact better with huge pages (not yet explicitly supported). (@jasone) + - Fold large and huge size classes together; only small and large size classes + remain. (@jasone) + - Unify the allocation paths, and merge most fast-path branching decisions. + (@davidtgoldblatt, @interwq) + - Embed per thread automatic tcache into thread-specific data, which reduces + conditional branches and dereferences. Also reorganize tcache to increase + fast-path data locality. (@interwq) + - Rewrite atomics to closely model the C11 API, convert various + synchronization from mutex-based to atomic, and use the explicit memory + ordering control to resolve various hypothetical races without increasing + synchronization overhead. (@davidtgoldblatt) + - Extensively optimize rtree via various methods: + + Add multiple layers of rtree lookup caching, since rtree lookups are now + part of fast-path deallocation. (@interwq) + + Determine rtree layout at compile time. (@jasone) + + Make the tree shallower for common configurations. (@jasone) + + Embed the root node in the top-level rtree data structure, thus avoiding + one level of indirection. (@jasone) + + Further specialize leaf elements as compared to internal node elements, + and directly embed extent metadata needed for fast-path deallocation. + (@jasone) + + Ignore leading always-zero address bits (architecture-specific). + (@jasone) + - Reorganize headers (ongoing work) to make them hermetic, and disentangle + various module dependencies. (@davidtgoldblatt) + - Convert various internal data structures such as size class metadata from + boot-time-initialized to compile-time-initialized. Propagate resulting data + structure simplifications, such as making arena metadata fixed-size. + (@jasone) + - Simplify size class lookups when constrained to size classes that are + multiples of the page size. This speeds lookups, but the primary benefit is + complexity reduction in code that was the source of numerous regressions. + (@jasone) + - Lock individual extents when possible for localized extent operations, + rather than relying on a top-level arena lock. (@davidtgoldblatt, @jasone) + - Use first fit layout policy instead of best fit, in order to improve + packing. (@jasone) + - If munmap(2) is not in use, use an exponential series to grow each arena's + virtual memory, so that the number of disjoint virtual memory mappings + remains low. (@jasone) + - Implement per arena base allocators, so that arenas never share any virtual + memory pages. (@jasone) + - Automatically generate private symbol name mangling macros. (@jasone) + + Incompatible changes: + - Replace chunk hooks with an expanded/normalized set of extent hooks. + (@jasone) + - Remove ratio-based purging. (@jasone) + - Remove --disable-tcache. (@jasone) + - Remove --disable-tls. (@jasone) + - Remove --enable-ivsalloc. (@jasone) + - Remove --with-lg-size-class-group. (@jasone) + - Remove --with-lg-tiny-min. (@jasone) + - Remove --disable-cc-silence. (@jasone) + - Remove --enable-code-coverage. (@jasone) + - Remove --disable-munmap (replaced by opt.retain). (@jasone) + - Remove Valgrind support. (@jasone) + - Remove quarantine support. (@jasone) + - Remove redzone support. (@jasone) + - Remove mallctl interfaces (various authors): + + config.munmap + + config.tcache + + config.tls + + config.valgrind + + opt.lg_chunk + + opt.purge + + opt.lg_dirty_mult + + opt.decay_time + + opt.quarantine + + opt.redzone + + opt.thp + + arena.<i>.lg_dirty_mult + + arena.<i>.decay_time + + arena.<i>.chunk_hooks + + arenas.initialized + + arenas.lg_dirty_mult + + arenas.decay_time + + arenas.bin.<i>.run_size + + arenas.nlruns + + arenas.lrun.<i>.size + + arenas.nhchunks + + arenas.hchunk.<i>.size + + arenas.extend + + stats.cactive + + stats.arenas.<i>.lg_dirty_mult + + stats.arenas.<i>.decay_time + + stats.arenas.<i>.metadata.{mapped,allocated} + + stats.arenas.<i>.{npurge,nmadvise,purged} + + stats.arenas.<i>.huge.{allocated,nmalloc,ndalloc,nrequests} + + stats.arenas.<i>.bins.<j>.{nruns,reruns,curruns} + + stats.arenas.<i>.lruns.<j>.{nmalloc,ndalloc,nrequests,curruns} + + stats.arenas.<i>.hchunks.<j>.{nmalloc,ndalloc,nrequests,curhchunks} + + Bug fixes: + - Improve interval-based profile dump triggering to dump only one profile when + a single allocation's size exceeds the interval. (@jasone) + - Use prefixed function names (as controlled by --with-jemalloc-prefix) when + pruning backtrace frames in jeprof. (@jasone) + +* 4.5.0 (February 28, 2017) + + This is the first release to benefit from much broader continuous integration + testing, thanks to @davidtgoldblatt. Had we had this testing infrastructure + in place for prior releases, it would have caught all of the most serious + regressions fixed by this release. + + New features: + - Add --disable-thp and the opt.thp mallctl to provide opt-out mechanisms for + transparent huge page integration. (@jasone) + - Update zone allocator integration to work with macOS 10.12. (@glandium) + - Restructure *CFLAGS configuration, so that CFLAGS behaves typically, and + EXTRA_CFLAGS provides a way to specify e.g. -Werror during building, but not + during configuration. (@jasone, @ronawho) + + Bug fixes: + - Fix DSS (sbrk(2)-based) allocation. This regression was first released in + 4.3.0. (@jasone) + - Handle race in per size class utilization computation. This functionality + was first released in 4.0.0. (@interwq) + - Fix lock order reversal during gdump. (@jasone) + - Fix/refactor tcache synchronization. This regression was first released in + 4.0.0. (@jasone) + - Fix various JSON-formatted malloc_stats_print() bugs. This functionality + was first released in 4.3.0. (@jasone) + - Fix huge-aligned allocation. This regression was first released in 4.4.0. + (@jasone) + - When transparent huge page integration is enabled, detect what state pages + start in according to the kernel's current operating mode, and only convert + arena chunks to non-huge during purging if that is not their initial state. + This functionality was first released in 4.4.0. (@jasone) + - Fix lg_chunk clamping for the --enable-cache-oblivious --disable-fill case. + This regression was first released in 4.0.0. (@jasone, @428desmo) + - Properly detect sparc64 when building for Linux. (@glaubitz) + +* 4.4.0 (December 3, 2016) + + New features: + - Add configure support for *-*-linux-android. (@cferris1000, @jasone) + - Add the --disable-syscall configure option, for use on systems that place + security-motivated limitations on syscall(2). (@jasone) + - Add support for Debian GNU/kFreeBSD. (@thesam) + + Optimizations: + - Add extent serial numbers and use them where appropriate as a sort key that + is higher priority than address, so that the allocation policy prefers older + extents. This tends to improve locality (decrease fragmentation) when + memory grows downward. (@jasone) + - Refactor madvise(2) configuration so that MADV_FREE is detected and utilized + on Linux 4.5 and newer. (@jasone) + - Mark partially purged arena chunks as non-huge-page. This improves + interaction with Linux's transparent huge page functionality. (@jasone) + + Bug fixes: + - Fix size class computations for edge conditions involving extremely large + allocations. This regression was first released in 4.0.0. (@jasone, + @ingvarha) + - Remove overly restrictive assertions related to the cactive statistic. This + regression was first released in 4.1.0. (@jasone) + - Implement a more reliable detection scheme for os_unfair_lock on macOS. + (@jszakmeister) + +* 4.3.1 (November 7, 2016) + + Bug fixes: + - Fix a severe virtual memory leak. This regression was first released in + 4.3.0. (@interwq, @jasone) + - Refactor atomic and prng APIs to restore support for 32-bit platforms that + use pre-C11 toolchains, e.g. FreeBSD's mips. (@jasone) + +* 4.3.0 (November 4, 2016) + + This is the first release that passes the test suite for multiple Windows + configurations, thanks in large part to @glandium setting up continuous + integration via AppVeyor (and Travis CI for Linux and OS X). + + New features: + - Add "J" (JSON) support to malloc_stats_print(). (@jasone) + - Add Cray compiler support. (@ronawho) + + Optimizations: + - Add/use adaptive spinning for bootstrapping and radix tree node + initialization. (@jasone) + + Bug fixes: + - Fix large allocation to search starting in the optimal size class heap, + which can substantially reduce virtual memory churn and fragmentation. This + regression was first released in 4.0.0. (@mjp41, @jasone) + - Fix stats.arenas.<i>.nthreads accounting. (@interwq) + - Fix and simplify decay-based purging. (@jasone) + - Make DSS (sbrk(2)-related) operations lockless, which resolves potential + deadlocks during thread exit. (@jasone) + - Fix over-sized allocation of radix tree leaf nodes. (@mjp41, @ogaun, + @jasone) + - Fix over-sized allocation of arena_t (plus associated stats) data + structures. (@jasone, @interwq) + - Fix EXTRA_CFLAGS to not affect configuration. (@jasone) + - Fix a Valgrind integration bug. (@ronawho) + - Disallow 0x5a junk filling when running in Valgrind. (@jasone) + - Fix a file descriptor leak on Linux. This regression was first released in + 4.2.0. (@vsarunas, @jasone) + - Fix static linking of jemalloc with glibc. (@djwatson) + - Use syscall(2) rather than {open,read,close}(2) during boot on Linux. This + works around other libraries' system call wrappers performing reentrant + allocation. (@kspinka, @Whissi, @jasone) + - Fix OS X default zone replacement to work with OS X 10.12. (@glandium, + @jasone) + - Fix cached memory management to avoid needless commit/decommit operations + during purging, which resolves permanent virtual memory map fragmentation + issues on Windows. (@mjp41, @jasone) + - Fix TSD fetches to avoid (recursive) allocation. This is relevant to + non-TLS and Windows configurations. (@jasone) + - Fix malloc_conf overriding to work on Windows. (@jasone) + - Forcibly disable lazy-lock on Windows (was forcibly *enabled*). (@jasone) + +* 4.2.1 (June 8, 2016) + + Bug fixes: + - Fix bootstrapping issues for configurations that require allocation during + tsd initialization (e.g. --disable-tls). (@cferris1000, @jasone) + - Fix gettimeofday() version of nstime_update(). (@ronawho) + - Fix Valgrind regressions in calloc() and chunk_alloc_wrapper(). (@ronawho) + - Fix potential VM map fragmentation regression. (@jasone) + - Fix opt_zero-triggered in-place huge reallocation zeroing. (@jasone) + - Fix heap profiling context leaks in reallocation edge cases. (@jasone) + +* 4.2.0 (May 12, 2016) + + New features: + - Add the arena.<i>.reset mallctl, which makes it possible to discard all of + an arena's allocations in a single operation. (@jasone) + - Add the stats.retained and stats.arenas.<i>.retained statistics. (@jasone) + - Add the --with-version configure option. (@jasone) + - Support --with-lg-page values larger than actual page size. (@jasone) + + Optimizations: + - Use pairing heaps rather than red-black trees for various hot data + structures. (@djwatson, @jasone) + - Streamline fast paths of rtree operations. (@jasone) + - Optimize the fast paths of calloc() and [m,d,sd]allocx(). (@jasone) + - Decommit unused virtual memory if the OS does not overcommit. (@jasone) + - Specify MAP_NORESERVE on Linux if [heuristic] overcommit is active, in order + to avoid unfortunate interactions during fork(2). (@jasone) + + Bug fixes: + - Fix chunk accounting related to triggering gdump profiles. (@jasone) + - Link against librt for clock_gettime(2) if glibc < 2.17. (@jasone) + - Scale leak report summary according to sampling probability. (@jasone) + +* 4.1.1 (May 3, 2016) + + This bugfix release resolves a variety of mostly minor issues, though the + bitmap fix is critical for 64-bit Windows. + + Bug fixes: + - Fix the linear scan version of bitmap_sfu() to shift by the proper amount + even when sizeof(long) is not the same as sizeof(void *), as on 64-bit + Windows. (@jasone) + - Fix hashing functions to avoid unaligned memory accesses (and resulting + crashes). This is relevant at least to some ARM-based platforms. + (@rkmisra) + - Fix fork()-related lock rank ordering reversals. These reversals were + unlikely to cause deadlocks in practice except when heap profiling was + enabled and active. (@jasone) + - Fix various chunk leaks in OOM code paths. (@jasone) + - Fix malloc_stats_print() to print opt.narenas correctly. (@jasone) + - Fix MSVC-specific build/test issues. (@rustyx, @yuslepukhin) + - Fix a variety of test failures that were due to test fragility rather than + core bugs. (@jasone) + +* 4.1.0 (February 28, 2016) + + This release is primarily about optimizations, but it also incorporates a lot + of portability-motivated refactoring and enhancements. Many people worked on + this release, to an extent that even with the omission here of minor changes + (see git revision history), and of the people who reported and diagnosed + issues, so much of the work was contributed that starting with this release, + changes are annotated with author credits to help reflect the collaborative + effort involved. + + New features: + - Implement decay-based unused dirty page purging, a major optimization with + mallctl API impact. This is an alternative to the existing ratio-based + unused dirty page purging, and is intended to eventually become the sole + purging mechanism. New mallctls: + + opt.purge + + opt.decay_time + + arena.<i>.decay + + arena.<i>.decay_time + + arenas.decay_time + + stats.arenas.<i>.decay_time + (@jasone, @cevans87) + - Add --with-malloc-conf, which makes it possible to embed a default + options string during configuration. This was motivated by the desire to + specify --with-malloc-conf=purge:decay , since the default must remain + purge:ratio until the 5.0.0 release. (@jasone) + - Add MS Visual Studio 2015 support. (@rustyx, @yuslepukhin) + - Make *allocx() size class overflow behavior defined. The maximum + size class is now less than PTRDIFF_MAX to protect applications against + numerical overflow, and all allocation functions are guaranteed to indicate + errors rather than potentially crashing if the request size exceeds the + maximum size class. (@jasone) + - jeprof: + + Add raw heap profile support. (@jasone) + + Add --retain and --exclude for backtrace symbol filtering. (@jasone) + + Optimizations: + - Optimize the fast path to combine various bootstrapping and configuration + checks and execute more streamlined code in the common case. (@interwq) + - Use linear scan for small bitmaps (used for small object tracking). In + addition to speeding up bitmap operations on 64-bit systems, this reduces + allocator metadata overhead by approximately 0.2%. (@djwatson) + - Separate arena_avail trees, which substantially speeds up run tree + operations. (@djwatson) + - Use memoization (boot-time-computed table) for run quantization. Separate + arena_avail trees reduced the importance of this optimization. (@jasone) + - Attempt mmap-based in-place huge reallocation. This can dramatically speed + up incremental huge reallocation. (@jasone) + + Incompatible changes: + - Make opt.narenas unsigned rather than size_t. (@jasone) + + Bug fixes: + - Fix stats.cactive accounting regression. (@rustyx, @jasone) + - Handle unaligned keys in hash(). This caused problems for some ARM systems. + (@jasone, @cferris1000) + - Refactor arenas array. In addition to fixing a fork-related deadlock, this + makes arena lookups faster and simpler. (@jasone) + - Move retained memory allocation out of the default chunk allocation + function, to a location that gets executed even if the application installs + a custom chunk allocation function. This resolves a virtual memory leak. + (@buchgr) + - Fix a potential tsd cleanup leak. (@cferris1000, @jasone) + - Fix run quantization. In practice this bug had no impact unless + applications requested memory with alignment exceeding one page. + (@jasone, @djwatson) + - Fix LinuxThreads-specific bootstrapping deadlock. (Cosmin Paraschiv) + - jeprof: + + Don't discard curl options if timeout is not defined. (@djwatson) + + Detect failed profile fetches. (@djwatson) + - Fix stats.arenas.<i>.{dss,lg_dirty_mult,decay_time,pactive,pdirty} for + --disable-stats case. (@jasone) + +* 4.0.4 (October 24, 2015) + + This bugfix release fixes another xallocx() regression. No other regressions + have come to light in over a month, so this is likely a good starting point + for people who prefer to wait for "dot one" releases with all the major issues + shaken out. + + Bug fixes: + - Fix xallocx(..., MALLOCX_ZERO to zero the last full trailing page of large + allocations that have been randomly assigned an offset of 0 when + --enable-cache-oblivious configure option is enabled. + +* 4.0.3 (September 24, 2015) + + This bugfix release continues the trend of xallocx() and heap profiling fixes. + + Bug fixes: + - Fix xallocx(..., MALLOCX_ZERO) to zero all trailing bytes of large + allocations when --enable-cache-oblivious configure option is enabled. + - Fix xallocx(..., MALLOCX_ZERO) to zero trailing bytes of huge allocations + when resizing from/to a size class that is not a multiple of the chunk size. + - Fix prof_tctx_dump_iter() to filter out nodes that were created after heap + profile dumping started. + - Work around a potentially bad thread-specific data initialization + interaction with NPTL (glibc's pthreads implementation). + +* 4.0.2 (September 21, 2015) + + This bugfix release addresses a few bugs specific to heap profiling. + + Bug fixes: + - Fix ixallocx_prof_sample() to never modify nor create sampled small + allocations. xallocx() is in general incapable of moving small allocations, + so this fix removes buggy code without loss of generality. + - Fix irallocx_prof_sample() to always allocate large regions, even when + alignment is non-zero. + - Fix prof_alloc_rollback() to read tdata from thread-specific data rather + than dereferencing a potentially invalid tctx. + +* 4.0.1 (September 15, 2015) + + This is a bugfix release that is somewhat high risk due to the amount of + refactoring required to address deep xallocx() problems. As a side effect of + these fixes, xallocx() now tries harder to partially fulfill requests for + optional extra space. Note that a couple of minor heap profiling + optimizations are included, but these are better thought of as performance + fixes that were integral to discovering most of the other bugs. + + Optimizations: + - Avoid a chunk metadata read in arena_prof_tctx_set(), since it is in the + fast path when heap profiling is enabled. Additionally, split a special + case out into arena_prof_tctx_reset(), which also avoids chunk metadata + reads. + - Optimize irallocx_prof() to optimistically update the sampler state. The + prior implementation appears to have been a holdover from when + rallocx()/xallocx() functionality was combined as rallocm(). + + Bug fixes: + - Fix TLS configuration such that it is enabled by default for platforms on + which it works correctly. + - Fix arenas_cache_cleanup() and arena_get_hard() to handle + allocation/deallocation within the application's thread-specific data + cleanup functions even after arenas_cache is torn down. + - Fix xallocx() bugs related to size+extra exceeding HUGE_MAXCLASS. + - Fix chunk purge hook calls for in-place huge shrinking reallocation to + specify the old chunk size rather than the new chunk size. This bug caused + no correctness issues for the default chunk purge function, but was + visible to custom functions set via the "arena.<i>.chunk_hooks" mallctl. + - Fix heap profiling bugs: + + Fix heap profiling to distinguish among otherwise identical sample sites + with interposed resets (triggered via the "prof.reset" mallctl). This bug + could cause data structure corruption that would most likely result in a + segfault. + + Fix irealloc_prof() to prof_alloc_rollback() on OOM. + + Make one call to prof_active_get_unlocked() per allocation event, and use + the result throughout the relevant functions that handle an allocation + event. Also add a missing check in prof_realloc(). These fixes protect + allocation events against concurrent prof_active changes. + + Fix ixallocx_prof() to pass usize_max and zero to ixallocx_prof_sample() + in the correct order. + + Fix prof_realloc() to call prof_free_sampled_object() after calling + prof_malloc_sample_object(). Prior to this fix, if tctx and old_tctx were + the same, the tctx could have been prematurely destroyed. + - Fix portability bugs: + + Don't bitshift by negative amounts when encoding/decoding run sizes in + chunk header maps. This affected systems with page sizes greater than 8 + KiB. + + Rename index_t to szind_t to avoid an existing type on Solaris. + + Add JEMALLOC_CXX_THROW to the memalign() function prototype, in order to + match glibc and avoid compilation errors when including both + jemalloc/jemalloc.h and malloc.h in C++ code. + + Don't assume that /bin/sh is appropriate when running size_classes.sh + during configuration. + + Consider __sparcv9 a synonym for __sparc64__ when defining LG_QUANTUM. + + Link tests to librt if it contains clock_gettime(2). + +* 4.0.0 (August 17, 2015) + + This version contains many speed and space optimizations, both minor and + major. The major themes are generalization, unification, and simplification. + Although many of these optimizations cause no visible behavior change, their + cumulative effect is substantial. + + New features: + - Normalize size class spacing to be consistent across the complete size + range. By default there are four size classes per size doubling, but this + is now configurable via the --with-lg-size-class-group option. Also add the + --with-lg-page, --with-lg-page-sizes, --with-lg-quantum, and + --with-lg-tiny-min options, which can be used to tweak page and size class + settings. Impacts: + + Worst case performance for incrementally growing/shrinking reallocation + is improved because there are far fewer size classes, and therefore + copying happens less often. + + Internal fragmentation is limited to 20% for all but the smallest size + classes (those less than four times the quantum). (1B + 4 KiB) + and (1B + 4 MiB) previously suffered nearly 50% internal fragmentation. + + Chunk fragmentation tends to be lower because there are fewer distinct run + sizes to pack. + - Add support for explicit tcaches. The "tcache.create", "tcache.flush", and + "tcache.destroy" mallctls control tcache lifetime and flushing, and the + MALLOCX_TCACHE(tc) and MALLOCX_TCACHE_NONE flags to the *allocx() API + control which tcache is used for each operation. + - Implement per thread heap profiling, as well as the ability to + enable/disable heap profiling on a per thread basis. Add the "prof.reset", + "prof.lg_sample", "thread.prof.name", "thread.prof.active", + "opt.prof_thread_active_init", "prof.thread_active_init", and + "thread.prof.active" mallctls. + - Add support for per arena application-specified chunk allocators, configured + via the "arena.<i>.chunk_hooks" mallctl. + - Refactor huge allocation to be managed by arenas, so that arenas now + function as general purpose independent allocators. This is important in + the context of user-specified chunk allocators, aside from the scalability + benefits. Related new statistics: + + The "stats.arenas.<i>.huge.allocated", "stats.arenas.<i>.huge.nmalloc", + "stats.arenas.<i>.huge.ndalloc", and "stats.arenas.<i>.huge.nrequests" + mallctls provide high level per arena huge allocation statistics. + + The "arenas.nhchunks", "arenas.hchunk.<i>.size", + "stats.arenas.<i>.hchunks.<j>.nmalloc", + "stats.arenas.<i>.hchunks.<j>.ndalloc", + "stats.arenas.<i>.hchunks.<j>.nrequests", and + "stats.arenas.<i>.hchunks.<j>.curhchunks" mallctls provide per size class + statistics. + - Add the 'util' column to malloc_stats_print() output, which reports the + proportion of available regions that are currently in use for each small + size class. + - Add "alloc" and "free" modes for for junk filling (see the "opt.junk" + mallctl), so that it is possible to separately enable junk filling for + allocation versus deallocation. + - Add the jemalloc-config script, which provides information about how + jemalloc was configured, and how to integrate it into application builds. + - Add metadata statistics, which are accessible via the "stats.metadata", + "stats.arenas.<i>.metadata.mapped", and + "stats.arenas.<i>.metadata.allocated" mallctls. + - Add the "stats.resident" mallctl, which reports the upper limit of + physically resident memory mapped by the allocator. + - Add per arena control over unused dirty page purging, via the + "arenas.lg_dirty_mult", "arena.<i>.lg_dirty_mult", and + "stats.arenas.<i>.lg_dirty_mult" mallctls. + - Add the "prof.gdump" mallctl, which makes it possible to toggle the gdump + feature on/off during program execution. + - Add sdallocx(), which implements sized deallocation. The primary + optimization over dallocx() is the removal of a metadata read, which often + suffers an L1 cache miss. + - Add missing header includes in jemalloc/jemalloc.h, so that applications + only have to #include <jemalloc/jemalloc.h>. + - Add support for additional platforms: + + Bitrig + + Cygwin + + DragonFlyBSD + + iOS + + OpenBSD + + OpenRISC/or1k + + Optimizations: + - Maintain dirty runs in per arena LRUs rather than in per arena trees of + dirty-run-containing chunks. In practice this change significantly reduces + dirty page purging volume. + - Integrate whole chunks into the unused dirty page purging machinery. This + reduces the cost of repeated huge allocation/deallocation, because it + effectively introduces a cache of chunks. + - Split the arena chunk map into two separate arrays, in order to increase + cache locality for the frequently accessed bits. + - Move small run metadata out of runs, into arena chunk headers. This reduces + run fragmentation, smaller runs reduce external fragmentation for small size + classes, and packed (less uniformly aligned) metadata layout improves CPU + cache set distribution. + - Randomly distribute large allocation base pointer alignment relative to page + boundaries in order to more uniformly utilize CPU cache sets. This can be + disabled via the --disable-cache-oblivious configure option, and queried via + the "config.cache_oblivious" mallctl. + - Micro-optimize the fast paths for the public API functions. + - Refactor thread-specific data to reside in a single structure. This assures + that only a single TLS read is necessary per call into the public API. + - Implement in-place huge allocation growing and shrinking. + - Refactor rtree (radix tree for chunk lookups) to be lock-free, and make + additional optimizations that reduce maximum lookup depth to one or two + levels. This resolves what was a concurrency bottleneck for per arena huge + allocation, because a global data structure is critical for determining + which arenas own which huge allocations. + + Incompatible changes: + - Replace --enable-cc-silence with --disable-cc-silence to suppress spurious + warnings by default. + - Assure that the constness of malloc_usable_size()'s return type matches that + of the system implementation. + - Change the heap profile dump format to support per thread heap profiling, + rename pprof to jeprof, and enhance it with the --thread=<n> option. As a + result, the bundled jeprof must now be used rather than the upstream + (gperftools) pprof. + - Disable "opt.prof_final" by default, in order to avoid atexit(3), which can + internally deadlock on some platforms. + - Change the "arenas.nlruns" mallctl type from size_t to unsigned. + - Replace the "stats.arenas.<i>.bins.<j>.allocated" mallctl with + "stats.arenas.<i>.bins.<j>.curregs". + - Ignore MALLOC_CONF in set{uid,gid,cap} binaries. + - Ignore MALLOCX_ARENA(a) in dallocx(), in favor of using the + MALLOCX_TCACHE(tc) and MALLOCX_TCACHE_NONE flags to control tcache usage. + + Removed features: + - Remove the *allocm() API, which is superseded by the *allocx() API. + - Remove the --enable-dss options, and make dss non-optional on all platforms + which support sbrk(2). + - Remove the "arenas.purge" mallctl, which was obsoleted by the + "arena.<i>.purge" mallctl in 3.1.0. + - Remove the unnecessary "opt.valgrind" mallctl; jemalloc automatically + detects whether it is running inside Valgrind. + - Remove the "stats.huge.allocated", "stats.huge.nmalloc", and + "stats.huge.ndalloc" mallctls. + - Remove the --enable-mremap option. + - Remove the "stats.chunks.current", "stats.chunks.total", and + "stats.chunks.high" mallctls. + + Bug fixes: + - Fix the cactive statistic to decrease (rather than increase) when active + memory decreases. This regression was first released in 3.5.0. + - Fix OOM handling in memalign() and valloc(). A variant of this bug existed + in all releases since 2.0.0, which introduced these functions. + - Fix an OOM-related regression in arena_tcache_fill_small(), which could + cause cache corruption on OOM. This regression was present in all releases + from 2.2.0 through 3.6.0. + - Fix size class overflow handling for malloc(), posix_memalign(), memalign(), + calloc(), and realloc() when profiling is enabled. + - Fix the "arena.<i>.dss" mallctl to return an error if "primary" or + "secondary" precedence is specified, but sbrk(2) is not supported. + - Fix fallback lg_floor() implementations to handle extremely large inputs. + - Ensure the default purgeable zone is after the default zone on OS X. + - Fix latent bugs in atomic_*(). + - Fix the "arena.<i>.dss" mallctl to handle read-only calls. + - Fix tls_model configuration to enable the initial-exec model when possible. + - Mark malloc_conf as a weak symbol so that the application can override it. + - Correctly detect glibc's adaptive pthread mutexes. + - Fix the --without-export configure option. + +* 3.6.0 (March 31, 2014) + + This version contains a critical bug fix for a regression present in 3.5.0 and + 3.5.1. + + Bug fixes: + - Fix a regression in arena_chunk_alloc() that caused crashes during + small/large allocation if chunk allocation failed. In the absence of this + bug, chunk allocation failure would result in allocation failure, e.g. NULL + return from malloc(). This regression was introduced in 3.5.0. + - Fix backtracing for gcc intrinsics-based backtracing by specifying + -fno-omit-frame-pointer to gcc. Note that the application (and all the + libraries it links to) must also be compiled with this option for + backtracing to be reliable. + - Use dss allocation precedence for huge allocations as well as small/large + allocations. + - Fix test assertion failure message formatting. This bug did not manifest on + x86_64 systems because of implementation subtleties in va_list. + - Fix inconsequential test failures for hash and SFMT code. + + New features: + - Support heap profiling on FreeBSD. This feature depends on the proc + filesystem being mounted during heap profile dumping. + +* 3.5.1 (February 25, 2014) + + This version primarily addresses minor bugs in test code. + + Bug fixes: + - Configure Solaris/Illumos to use MADV_FREE. + - Fix junk filling for mremap(2)-based huge reallocation. This is only + relevant if configuring with the --enable-mremap option specified. + - Avoid compilation failure if 'restrict' C99 keyword is not supported by the + compiler. + - Add a configure test for SSE2 rather than assuming it is usable on i686 + systems. This fixes test compilation errors, especially on 32-bit Linux + systems. + - Fix mallctl argument size mismatches (size_t vs. uint64_t) in the stats unit + test. + - Fix/remove flawed alignment-related overflow tests. + - Prevent compiler optimizations that could change backtraces in the + prof_accum unit test. + +* 3.5.0 (January 22, 2014) + + This version focuses on refactoring and automated testing, though it also + includes some non-trivial heap profiling optimizations not mentioned below. + + New features: + - Add the *allocx() API, which is a successor to the experimental *allocm() + API. The *allocx() functions are slightly simpler to use because they have + fewer parameters, they directly return the results of primary interest, and + mallocx()/rallocx() avoid the strict aliasing pitfall that + allocm()/rallocm() share with posix_memalign(). Note that *allocm() is + slated for removal in the next non-bugfix release. + - Add support for LinuxThreads. + + Bug fixes: + - Unless heap profiling is enabled, disable floating point code and don't link + with libm. This, in combination with e.g. EXTRA_CFLAGS=-mno-sse on x64 + systems, makes it possible to completely disable floating point register + use. Some versions of glibc neglect to save/restore caller-saved floating + point registers during dynamic lazy symbol loading, and the symbol loading + code uses whatever malloc the application happens to have linked/loaded + with, the result being potential floating point register corruption. + - Report ENOMEM rather than EINVAL if an OOM occurs during heap profiling + backtrace creation in imemalign(). This bug impacted posix_memalign() and + aligned_alloc(). + - Fix a file descriptor leak in a prof_dump_maps() error path. + - Fix prof_dump() to close the dump file descriptor for all relevant error + paths. + - Fix rallocm() to use the arena specified by the ALLOCM_ARENA(s) flag for + allocation, not just deallocation. + - Fix a data race for large allocation stats counters. + - Fix a potential infinite loop during thread exit. This bug occurred on + Solaris, and could affect other platforms with similar pthreads TSD + implementations. + - Don't junk-fill reallocations unless usable size changes. This fixes a + violation of the *allocx()/*allocm() semantics. + - Fix growing large reallocation to junk fill new space. + - Fix huge deallocation to junk fill when munmap is disabled. + - Change the default private namespace prefix from empty to je_, and change + --with-private-namespace-prefix so that it prepends an additional prefix + rather than replacing je_. This reduces the likelihood of applications + which statically link jemalloc experiencing symbol name collisions. + - Add missing private namespace mangling (relevant when + --with-private-namespace is specified). + - Add and use JEMALLOC_INLINE_C so that static inline functions are marked as + static even for debug builds. + - Add a missing mutex unlock in a malloc_init_hard() error path. In practice + this error path is never executed. + - Fix numerous bugs in malloc_strotumax() error handling/reporting. These + bugs had no impact except for malformed inputs. + - Fix numerous bugs in malloc_snprintf(). These bugs were not exercised by + existing calls, so they had no impact. + +* 3.4.1 (October 20, 2013) + + Bug fixes: + - Fix a race in the "arenas.extend" mallctl that could cause memory corruption + of internal data structures and subsequent crashes. + - Fix Valgrind integration flaws that caused Valgrind warnings about reads of + uninitialized memory in: + + arena chunk headers + + internal zero-initialized data structures (relevant to tcache and prof + code) + - Preserve errno during the first allocation. A readlink(2) call during + initialization fails unless /etc/malloc.conf exists, so errno was typically + set during the first allocation prior to this fix. + - Fix compilation warnings reported by gcc 4.8.1. + +* 3.4.0 (June 2, 2013) + + This version is essentially a small bugfix release, but the addition of + aarch64 support requires that the minor version be incremented. + + Bug fixes: + - Fix race-triggered deadlocks in chunk_record(). These deadlocks were + typically triggered by multiple threads concurrently deallocating huge + objects. + + New features: + - Add support for the aarch64 architecture. + +* 3.3.1 (March 6, 2013) + + This version fixes bugs that are typically encountered only when utilizing + custom run-time options. + + Bug fixes: + - Fix a locking order bug that could cause deadlock during fork if heap + profiling were enabled. + - Fix a chunk recycling bug that could cause the allocator to lose track of + whether a chunk was zeroed. On FreeBSD, NetBSD, and OS X, it could cause + corruption if allocating via sbrk(2) (unlikely unless running with the + "dss:primary" option specified). This was completely harmless on Linux + unless using mlockall(2) (and unlikely even then, unless the + --disable-munmap configure option or the "dss:primary" option was + specified). This regression was introduced in 3.1.0 by the + mlockall(2)/madvise(2) interaction fix. + - Fix TLS-related memory corruption that could occur during thread exit if the + thread never allocated memory. Only the quarantine and prof facilities were + susceptible. + - Fix two quarantine bugs: + + Internal reallocation of the quarantined object array leaked the old + array. + + Reallocation failure for internal reallocation of the quarantined object + array (very unlikely) resulted in memory corruption. + - Fix Valgrind integration to annotate all internally allocated memory in a + way that keeps Valgrind happy about internal data structure access. + - Fix building for s390 systems. + +* 3.3.0 (January 23, 2013) + + This version includes a few minor performance improvements in addition to the + listed new features and bug fixes. + + New features: + - Add clipping support to lg_chunk option processing. + - Add the --enable-ivsalloc option. + - Add the --without-export option. + - Add the --disable-zone-allocator option. + + Bug fixes: + - Fix "arenas.extend" mallctl to output the number of arenas. + - Fix chunk_recycle() to unconditionally inform Valgrind that returned memory + is undefined. + - Fix build break on FreeBSD related to alloca.h. + +* 3.2.0 (November 9, 2012) + + In addition to a couple of bug fixes, this version modifies page run + allocation and dirty page purging algorithms in order to better control + page-level virtual memory fragmentation. + + Incompatible changes: + - Change the "opt.lg_dirty_mult" default from 5 to 3 (32:1 to 8:1). + + Bug fixes: + - Fix dss/mmap allocation precedence code to use recyclable mmap memory only + after primary dss allocation fails. + - Fix deadlock in the "arenas.purge" mallctl. This regression was introduced + in 3.1.0 by the addition of the "arena.<i>.purge" mallctl. + +* 3.1.0 (October 16, 2012) + + New features: + - Auto-detect whether running inside Valgrind, thus removing the need to + manually specify MALLOC_CONF=valgrind:true. + - Add the "arenas.extend" mallctl, which allows applications to create + manually managed arenas. + - Add the ALLOCM_ARENA() flag for {,r,d}allocm(). + - Add the "opt.dss", "arena.<i>.dss", and "stats.arenas.<i>.dss" mallctls, + which provide control over dss/mmap precedence. + - Add the "arena.<i>.purge" mallctl, which obsoletes "arenas.purge". + - Define LG_QUANTUM for hppa. + + Incompatible changes: + - Disable tcache by default if running inside Valgrind, in order to avoid + making unallocated objects appear reachable to Valgrind. + - Drop const from malloc_usable_size() argument on Linux. + + Bug fixes: + - Fix heap profiling crash if sampled object is freed via realloc(p, 0). + - Remove const from __*_hook variable declarations, so that glibc can modify + them during process forking. + - Fix mlockall(2)/madvise(2) interaction. + - Fix fork(2)-related deadlocks. + - Fix error return value for "thread.tcache.enabled" mallctl. + +* 3.0.0 (May 11, 2012) + + Although this version adds some major new features, the primary focus is on + internal code cleanup that facilitates maintainability and portability, most + of which is not reflected in the ChangeLog. This is the first release to + incorporate substantial contributions from numerous other developers, and the + result is a more broadly useful allocator (see the git revision history for + contribution details). Note that the license has been unified, thanks to + Facebook granting a license under the same terms as the other copyright + holders (see COPYING). + + New features: + - Implement Valgrind support, redzones, and quarantine. + - Add support for additional platforms: + + FreeBSD + + Mac OS X Lion + + MinGW + + Windows (no support yet for replacing the system malloc) + - Add support for additional architectures: + + MIPS + + SH4 + + Tilera + - Add support for cross compiling. + - Add nallocm(), which rounds a request size up to the nearest size class + without actually allocating. + - Implement aligned_alloc() (blame C11). + - Add the "thread.tcache.enabled" mallctl. + - Add the "opt.prof_final" mallctl. + - Update pprof (from gperftools 2.0). + - Add the --with-mangling option. + - Add the --disable-experimental option. + - Add the --disable-munmap option, and make it the default on Linux. + - Add the --enable-mremap option, which disables use of mremap(2) by default. + + Incompatible changes: + - Enable stats by default. + - Enable fill by default. + - Disable lazy locking by default. + - Rename the "tcache.flush" mallctl to "thread.tcache.flush". + - Rename the "arenas.pagesize" mallctl to "arenas.page". + - Change the "opt.lg_prof_sample" default from 0 to 19 (1 B to 512 KiB). + - Change the "opt.prof_accum" default from true to false. + + Removed features: + - Remove the swap feature, including the "config.swap", "swap.avail", + "swap.prezeroed", "swap.nfds", and "swap.fds" mallctls. + - Remove highruns statistics, including the + "stats.arenas.<i>.bins.<j>.highruns" and + "stats.arenas.<i>.lruns.<j>.highruns" mallctls. + - As part of small size class refactoring, remove the "opt.lg_[qc]space_max", + "arenas.cacheline", "arenas.subpage", "arenas.[tqcs]space_{min,max}", and + "arenas.[tqcs]bins" mallctls. + - Remove the "arenas.chunksize" mallctl. + - Remove the "opt.lg_prof_tcmax" option. + - Remove the "opt.lg_prof_bt_max" option. + - Remove the "opt.lg_tcache_gc_sweep" option. + - Remove the --disable-tiny option, including the "config.tiny" mallctl. + - Remove the --enable-dynamic-page-shift configure option. + - Remove the --enable-sysv configure option. + + Bug fixes: + - Fix a statistics-related bug in the "thread.arena" mallctl that could cause + invalid statistics and crashes. + - Work around TLS deallocation via free() on Linux. This bug could cause + write-after-free memory corruption. + - Fix a potential deadlock that could occur during interval- and + growth-triggered heap profile dumps. + - Fix large calloc() zeroing bugs due to dropping chunk map unzeroed flags. + - Fix chunk_alloc_dss() to stop claiming memory is zeroed. This bug could + cause memory corruption and crashes with --enable-dss specified. + - Fix fork-related bugs that could cause deadlock in children between fork + and exec. + - Fix malloc_stats_print() to honor 'b' and 'l' in the opts parameter. + - Fix realloc(p, 0) to act like free(p). + - Do not enforce minimum alignment in memalign(). + - Check for NULL pointer in malloc_usable_size(). + - Fix an off-by-one heap profile statistics bug that could be observed in + interval- and growth-triggered heap profiles. + - Fix the "epoch" mallctl to update cached stats even if the passed in epoch + is 0. + - Fix bin->runcur management to fix a layout policy bug. This bug did not + affect correctness. + - Fix a bug in choose_arena_hard() that potentially caused more arenas to be + initialized than necessary. + - Add missing "opt.lg_tcache_max" mallctl implementation. + - Use glibc allocator hooks to make mixed allocator usage less likely. + - Fix build issues for --disable-tcache. + - Don't mangle pthread_create() when --with-private-namespace is specified. + +* 2.2.5 (November 14, 2011) + + Bug fixes: + - Fix huge_ralloc() race when using mremap(2). This is a serious bug that + could cause memory corruption and/or crashes. + - Fix huge_ralloc() to maintain chunk statistics. + - Fix malloc_stats_print(..., "a") output. + +* 2.2.4 (November 5, 2011) + + Bug fixes: + - Initialize arenas_tsd before using it. This bug existed for 2.2.[0-3], as + well as for --disable-tls builds in earlier releases. + - Do not assume a 4 KiB page size in test/rallocm.c. + +* 2.2.3 (August 31, 2011) + + This version fixes numerous bugs related to heap profiling. + + Bug fixes: + - Fix a prof-related race condition. This bug could cause memory corruption, + but only occurred in non-default configurations (prof_accum:false). + - Fix off-by-one backtracing issues (make sure that prof_alloc_prep() is + excluded from backtraces). + - Fix a prof-related bug in realloc() (only triggered by OOM errors). + - Fix prof-related bugs in allocm() and rallocm(). + - Fix prof_tdata_cleanup() for --disable-tls builds. + - Fix a relative include path, to fix objdir builds. + +* 2.2.2 (July 30, 2011) + + Bug fixes: + - Fix a build error for --disable-tcache. + - Fix assertions in arena_purge() (for real this time). + - Add the --with-private-namespace option. This is a workaround for symbol + conflicts that can inadvertently arise when using static libraries. + +* 2.2.1 (March 30, 2011) + + Bug fixes: + - Implement atomic operations for x86/x64. This fixes compilation failures + for versions of gcc that are still in wide use. + - Fix an assertion in arena_purge(). + +* 2.2.0 (March 22, 2011) + + This version incorporates several improvements to algorithms and data + structures that tend to reduce fragmentation and increase speed. + + New features: + - Add the "stats.cactive" mallctl. + - Update pprof (from google-perftools 1.7). + - Improve backtracing-related configuration logic, and add the + --disable-prof-libgcc option. + + Bug fixes: + - Change default symbol visibility from "internal", to "hidden", which + decreases the overhead of library-internal function calls. + - Fix symbol visibility so that it is also set on OS X. + - Fix a build dependency regression caused by the introduction of the .pic.o + suffix for PIC object files. + - Add missing checks for mutex initialization failures. + - Don't use libgcc-based backtracing except on x64, where it is known to work. + - Fix deadlocks on OS X that were due to memory allocation in + pthread_mutex_lock(). + - Heap profiling-specific fixes: + + Fix memory corruption due to integer overflow in small region index + computation, when using a small enough sample interval that profiling + context pointers are stored in small run headers. + + Fix a bootstrap ordering bug that only occurred with TLS disabled. + + Fix a rallocm() rsize bug. + + Fix error detection bugs for aligned memory allocation. + +* 2.1.3 (March 14, 2011) + + Bug fixes: + - Fix a cpp logic regression (due to the "thread.{de,}allocatedp" mallctl fix + for OS X in 2.1.2). + - Fix a "thread.arena" mallctl bug. + - Fix a thread cache stats merging bug. + +* 2.1.2 (March 2, 2011) + + Bug fixes: + - Fix "thread.{de,}allocatedp" mallctl for OS X. + - Add missing jemalloc.a to build system. + +* 2.1.1 (January 31, 2011) + + Bug fixes: + - Fix aligned huge reallocation (affected allocm()). + - Fix the ALLOCM_LG_ALIGN macro definition. + - Fix a heap dumping deadlock. + - Fix a "thread.arena" mallctl bug. + +* 2.1.0 (December 3, 2010) + + This version incorporates some optimizations that can't quite be considered + bug fixes. + + New features: + - Use Linux's mremap(2) for huge object reallocation when possible. + - Avoid locking in mallctl*() when possible. + - Add the "thread.[de]allocatedp" mallctl's. + - Convert the manual page source from roff to DocBook, and generate both roff + and HTML manuals. + + Bug fixes: + - Fix a crash due to incorrect bootstrap ordering. This only impacted + --enable-debug --enable-dss configurations. + - Fix a minor statistics bug for mallctl("swap.avail", ...). + +* 2.0.1 (October 29, 2010) + + Bug fixes: + - Fix a race condition in heap profiling that could cause undefined behavior + if "opt.prof_accum" were disabled. + - Add missing mutex unlocks for some OOM error paths in the heap profiling + code. + - Fix a compilation error for non-C99 builds. + +* 2.0.0 (October 24, 2010) + + This version focuses on the experimental *allocm() API, and on improved + run-time configuration/introspection. Nonetheless, numerous performance + improvements are also included. + + New features: + - Implement the experimental {,r,s,d}allocm() API, which provides a superset + of the functionality available via malloc(), calloc(), posix_memalign(), + realloc(), malloc_usable_size(), and free(). These functions can be used to + allocate/reallocate aligned zeroed memory, ask for optional extra memory + during reallocation, prevent object movement during reallocation, etc. + - Replace JEMALLOC_OPTIONS/JEMALLOC_PROF_PREFIX with MALLOC_CONF, which is + more human-readable, and more flexible. For example: + JEMALLOC_OPTIONS=AJP + is now: + MALLOC_CONF=abort:true,fill:true,stats_print:true + - Port to Apple OS X. Sponsored by Mozilla. + - Make it possible for the application to control thread-->arena mappings via + the "thread.arena" mallctl. + - Add compile-time support for all TLS-related functionality via pthreads TSD. + This is mainly of interest for OS X, which does not support TLS, but has a + TSD implementation with similar performance. + - Override memalign() and valloc() if they are provided by the system. + - Add the "arenas.purge" mallctl, which can be used to synchronously purge all + dirty unused pages. + - Make cumulative heap profiling data optional, so that it is possible to + limit the amount of memory consumed by heap profiling data structures. + - Add per thread allocation counters that can be accessed via the + "thread.allocated" and "thread.deallocated" mallctls. + + Incompatible changes: + - Remove JEMALLOC_OPTIONS and malloc_options (see MALLOC_CONF above). + - Increase default backtrace depth from 4 to 128 for heap profiling. + - Disable interval-based profile dumps by default. + + Bug fixes: + - Remove bad assertions in fork handler functions. These assertions could + cause aborts for some combinations of configure settings. + - Fix strerror_r() usage to deal with non-standard semantics in GNU libc. + - Fix leak context reporting. This bug tended to cause the number of contexts + to be underreported (though the reported number of objects and bytes were + correct). + - Fix a realloc() bug for large in-place growing reallocation. This bug could + cause memory corruption, but it was hard to trigger. + - Fix an allocation bug for small allocations that could be triggered if + multiple threads raced to create a new run of backing pages. + - Enhance the heap profiler to trigger samples based on usable size, rather + than request size. + - Fix a heap profiling bug due to sometimes losing track of requested object + size for sampled objects. + +* 1.0.3 (August 12, 2010) + + Bug fixes: + - Fix the libunwind-based implementation of stack backtracing (used for heap + profiling). This bug could cause zero-length backtraces to be reported. + - Add a missing mutex unlock in library initialization code. If multiple + threads raced to initialize malloc, some of them could end up permanently + blocked. + +* 1.0.2 (May 11, 2010) + + Bug fixes: + - Fix junk filling of large objects, which could cause memory corruption. + - Add MAP_NORESERVE support for chunk mapping, because otherwise virtual + memory limits could cause swap file configuration to fail. Contributed by + Jordan DeLong. + +* 1.0.1 (April 14, 2010) + + Bug fixes: + - Fix compilation when --enable-fill is specified. + - Fix threads-related profiling bugs that affected accuracy and caused memory + to be leaked during thread exit. + - Fix dirty page purging race conditions that could cause crashes. + - Fix crash in tcache flushing code during thread destruction. + +* 1.0.0 (April 11, 2010) + + This release focuses on speed and run-time introspection. Numerous + algorithmic improvements make this release substantially faster than its + predecessors. + + New features: + - Implement autoconf-based configuration system. + - Add mallctl*(), for the purposes of introspection and run-time + configuration. + - Make it possible for the application to manually flush a thread's cache, via + the "tcache.flush" mallctl. + - Base maximum dirty page count on proportion of active memory. + - Compute various additional run-time statistics, including per size class + statistics for large objects. + - Expose malloc_stats_print(), which can be called repeatedly by the + application. + - Simplify the malloc_message() signature to only take one string argument, + and incorporate an opaque data pointer argument for use by the application + in combination with malloc_stats_print(). + - Add support for allocation backed by one or more swap files, and allow the + application to disable over-commit if swap files are in use. + - Implement allocation profiling and leak checking. + + Removed features: + - Remove the dynamic arena rebalancing code, since thread-specific caching + reduces its utility. + + Bug fixes: + - Modify chunk allocation to work when address space layout randomization + (ASLR) is in use. + - Fix thread cleanup bugs related to TLS destruction. + - Handle 0-size allocation requests in posix_memalign(). + - Fix a chunk leak. The leaked chunks were never touched, so this impacted + virtual memory usage, but not physical memory usage. + +* linux_2008082[78]a (August 27/28, 2008) + + These snapshot releases are the simple result of incorporating Linux-specific + support into the FreeBSD malloc sources. + +-------------------------------------------------------------------------------- +vim:filetype=text:textwidth=80 |