Update Changelog for 5.2.0.
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https://github.com/jemalloc/jemalloc
-* 5.1.0 (May 4th, 2018)
+* 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
