1 Following are change highlights associated with official releases. Important
2 bug fixes are all mentioned, but some internal enhancements are omitted here for
3 brevity. Much more detail can be found in the git revision history:
5 https://github.com/jemalloc/jemalloc
7 * 4.1.0 (February 28, 2016)
9 This release is primarily about optimizations, but it also incorporates a lot
10 of portability-motivated refactoring and enhancements. Many people worked on
11 this release, to an extent that even with the omission here of minor changes
12 (see git revision history), and of the people who reported and diagnosed
13 issues, so much of the work was contributed that starting with this release,
14 changes are annotated with author credits to help reflect the collaborative
18 - Implement decay-based unused dirty page purging, a major optimization with
19 mallctl API impact. This is an alternative to the existing ratio-based
20 unused dirty page purging, and is intended to eventually become the sole
21 purging mechanism. New mallctls:
25 + arena.<i>.decay_time
27 + stats.arenas.<i>.decay_time
29 - Add --with-malloc-conf, which makes it possible to embed a default
30 options string during configuration. This was motivated by the desire to
31 specify --with-malloc-conf=purge:decay , since the default must remain
32 purge:ratio until the 5.0.0 release. (@jasone)
33 - Add MS Visual Studio 2015 support. (@rustyx, @yuslepukhin)
34 - Make *allocx() size class overflow behavior defined. The maximum
35 size class is now less than PTRDIFF_MAX to protect applications against
36 numerical overflow, and all allocation functions are guaranteed to indicate
37 errors rather than potentially crashing if the request size exceeds the
38 maximum size class. (@jasone)
40 + Add raw heap profile support. (@jasone)
41 + Add --retain and --exclude for backtrace symbol filtering. (@jasone)
44 - Optimize the fast path to combine various bootstrapping and configuration
45 checks and execute more streamlined code in the common case. (@interwq)
46 - Use linear scan for small bitmaps (used for small object tracking). In
47 addition to speeding up bitmap operations on 64-bit systems, this reduces
48 allocator metadata overhead by approximately 0.2%. (@djwatson)
49 - Separate arena_avail trees, which substantially speeds up run tree
50 operations. (@djwatson)
51 - Use memoization (boot-time-computed table) for run quantization. Separate
52 arena_avail trees reduced the importance of this optimization. (@jasone)
53 - Attempt mmap-based in-place huge reallocation. This can dramatically speed
54 up incremental huge reallocation. (@jasone)
57 - Make opt.narenas unsigned rather than size_t. (@jasone)
60 - Fix stats.cactive accounting regression. (@rustyx, @jasone)
61 - Handle unaligned keys in hash(). This caused problems for some ARM systems.
62 (@jasone, Christopher Ferris)
63 - Refactor arenas array. In addition to fixing a fork-related deadlock, this
64 makes arena lookups faster and simpler. (@jasone)
65 - Move retained memory allocation out of the default chunk allocation
66 function, to a location that gets executed even if the application installs
67 a custom chunk allocation function. This resolves a virtual memory leak.
69 - Fix a potential tsd cleanup leak. (Christopher Ferris, @jasone)
70 - Fix run quantization. In practice this bug had no impact unless
71 applications requested memory with alignment exceeding one page.
73 - Fix LinuxThreads-specific bootstrapping deadlock. (Cosmin Paraschiv)
75 + Don't discard curl options if timeout is not defined. (@djwatson)
76 + Detect failed profile fetches. (@djwatson)
77 - Fix stats.arenas.<i>.{dss,lg_dirty_mult,decay_time,pactive,pdirty} for
78 --disable-stats case. (@jasone)
80 * 4.0.4 (October 24, 2015)
82 This bugfix release fixes another xallocx() regression. No other regressions
83 have come to light in over a month, so this is likely a good starting point
84 for people who prefer to wait for "dot one" releases with all the major issues
88 - Fix xallocx(..., MALLOCX_ZERO to zero the last full trailing page of large
89 allocations that have been randomly assigned an offset of 0 when
90 --enable-cache-oblivious configure option is enabled.
92 * 4.0.3 (September 24, 2015)
94 This bugfix release continues the trend of xallocx() and heap profiling fixes.
97 - Fix xallocx(..., MALLOCX_ZERO) to zero all trailing bytes of large
98 allocations when --enable-cache-oblivious configure option is enabled.
99 - Fix xallocx(..., MALLOCX_ZERO) to zero trailing bytes of huge allocations
100 when resizing from/to a size class that is not a multiple of the chunk size.
101 - Fix prof_tctx_dump_iter() to filter out nodes that were created after heap
102 profile dumping started.
103 - Work around a potentially bad thread-specific data initialization
104 interaction with NPTL (glibc's pthreads implementation).
106 * 4.0.2 (September 21, 2015)
108 This bugfix release addresses a few bugs specific to heap profiling.
111 - Fix ixallocx_prof_sample() to never modify nor create sampled small
112 allocations. xallocx() is in general incapable of moving small allocations,
113 so this fix removes buggy code without loss of generality.
114 - Fix irallocx_prof_sample() to always allocate large regions, even when
115 alignment is non-zero.
116 - Fix prof_alloc_rollback() to read tdata from thread-specific data rather
117 than dereferencing a potentially invalid tctx.
119 * 4.0.1 (September 15, 2015)
121 This is a bugfix release that is somewhat high risk due to the amount of
122 refactoring required to address deep xallocx() problems. As a side effect of
123 these fixes, xallocx() now tries harder to partially fulfill requests for
124 optional extra space. Note that a couple of minor heap profiling
125 optimizations are included, but these are better thought of as performance
126 fixes that were integral to disovering most of the other bugs.
129 - Avoid a chunk metadata read in arena_prof_tctx_set(), since it is in the
130 fast path when heap profiling is enabled. Additionally, split a special
131 case out into arena_prof_tctx_reset(), which also avoids chunk metadata
133 - Optimize irallocx_prof() to optimistically update the sampler state. The
134 prior implementation appears to have been a holdover from when
135 rallocx()/xallocx() functionality was combined as rallocm().
138 - Fix TLS configuration such that it is enabled by default for platforms on
139 which it works correctly.
140 - Fix arenas_cache_cleanup() and arena_get_hard() to handle
141 allocation/deallocation within the application's thread-specific data
142 cleanup functions even after arenas_cache is torn down.
143 - Fix xallocx() bugs related to size+extra exceeding HUGE_MAXCLASS.
144 - Fix chunk purge hook calls for in-place huge shrinking reallocation to
145 specify the old chunk size rather than the new chunk size. This bug caused
146 no correctness issues for the default chunk purge function, but was
147 visible to custom functions set via the "arena.<i>.chunk_hooks" mallctl.
148 - Fix heap profiling bugs:
149 + Fix heap profiling to distinguish among otherwise identical sample sites
150 with interposed resets (triggered via the "prof.reset" mallctl). This bug
151 could cause data structure corruption that would most likely result in a
153 + Fix irealloc_prof() to prof_alloc_rollback() on OOM.
154 + Make one call to prof_active_get_unlocked() per allocation event, and use
155 the result throughout the relevant functions that handle an allocation
156 event. Also add a missing check in prof_realloc(). These fixes protect
157 allocation events against concurrent prof_active changes.
158 + Fix ixallocx_prof() to pass usize_max and zero to ixallocx_prof_sample()
159 in the correct order.
160 + Fix prof_realloc() to call prof_free_sampled_object() after calling
161 prof_malloc_sample_object(). Prior to this fix, if tctx and old_tctx were
162 the same, the tctx could have been prematurely destroyed.
163 - Fix portability bugs:
164 + Don't bitshift by negative amounts when encoding/decoding run sizes in
165 chunk header maps. This affected systems with page sizes greater than 8
167 + Rename index_t to szind_t to avoid an existing type on Solaris.
168 + Add JEMALLOC_CXX_THROW to the memalign() function prototype, in order to
169 match glibc and avoid compilation errors when including both
170 jemalloc/jemalloc.h and malloc.h in C++ code.
171 + Don't assume that /bin/sh is appropriate when running size_classes.sh
172 during configuration.
173 + Consider __sparcv9 a synonym for __sparc64__ when defining LG_QUANTUM.
174 + Link tests to librt if it contains clock_gettime(2).
176 * 4.0.0 (August 17, 2015)
178 This version contains many speed and space optimizations, both minor and
179 major. The major themes are generalization, unification, and simplification.
180 Although many of these optimizations cause no visible behavior change, their
181 cumulative effect is substantial.
184 - Normalize size class spacing to be consistent across the complete size
185 range. By default there are four size classes per size doubling, but this
186 is now configurable via the --with-lg-size-class-group option. Also add the
187 --with-lg-page, --with-lg-page-sizes, --with-lg-quantum, and
188 --with-lg-tiny-min options, which can be used to tweak page and size class
190 + Worst case performance for incrementally growing/shrinking reallocation
191 is improved because there are far fewer size classes, and therefore
192 copying happens less often.
193 + Internal fragmentation is limited to 20% for all but the smallest size
194 classes (those less than four times the quantum). (1B + 4 KiB)
195 and (1B + 4 MiB) previously suffered nearly 50% internal fragmentation.
196 + Chunk fragmentation tends to be lower because there are fewer distinct run
198 - Add support for explicit tcaches. The "tcache.create", "tcache.flush", and
199 "tcache.destroy" mallctls control tcache lifetime and flushing, and the
200 MALLOCX_TCACHE(tc) and MALLOCX_TCACHE_NONE flags to the *allocx() API
201 control which tcache is used for each operation.
202 - Implement per thread heap profiling, as well as the ability to
203 enable/disable heap profiling on a per thread basis. Add the "prof.reset",
204 "prof.lg_sample", "thread.prof.name", "thread.prof.active",
205 "opt.prof_thread_active_init", "prof.thread_active_init", and
206 "thread.prof.active" mallctls.
207 - Add support for per arena application-specified chunk allocators, configured
208 via the "arena.<i>.chunk_hooks" mallctl.
209 - Refactor huge allocation to be managed by arenas, so that arenas now
210 function as general purpose independent allocators. This is important in
211 the context of user-specified chunk allocators, aside from the scalability
212 benefits. Related new statistics:
213 + The "stats.arenas.<i>.huge.allocated", "stats.arenas.<i>.huge.nmalloc",
214 "stats.arenas.<i>.huge.ndalloc", and "stats.arenas.<i>.huge.nrequests"
215 mallctls provide high level per arena huge allocation statistics.
216 + The "arenas.nhchunks", "arenas.hchunk.<i>.size",
217 "stats.arenas.<i>.hchunks.<j>.nmalloc",
218 "stats.arenas.<i>.hchunks.<j>.ndalloc",
219 "stats.arenas.<i>.hchunks.<j>.nrequests", and
220 "stats.arenas.<i>.hchunks.<j>.curhchunks" mallctls provide per size class
222 - Add the 'util' column to malloc_stats_print() output, which reports the
223 proportion of available regions that are currently in use for each small
225 - Add "alloc" and "free" modes for for junk filling (see the "opt.junk"
226 mallctl), so that it is possible to separately enable junk filling for
227 allocation versus deallocation.
228 - Add the jemalloc-config script, which provides information about how
229 jemalloc was configured, and how to integrate it into application builds.
230 - Add metadata statistics, which are accessible via the "stats.metadata",
231 "stats.arenas.<i>.metadata.mapped", and
232 "stats.arenas.<i>.metadata.allocated" mallctls.
233 - Add the "stats.resident" mallctl, which reports the upper limit of
234 physically resident memory mapped by the allocator.
235 - Add per arena control over unused dirty page purging, via the
236 "arenas.lg_dirty_mult", "arena.<i>.lg_dirty_mult", and
237 "stats.arenas.<i>.lg_dirty_mult" mallctls.
238 - Add the "prof.gdump" mallctl, which makes it possible to toggle the gdump
239 feature on/off during program execution.
240 - Add sdallocx(), which implements sized deallocation. The primary
241 optimization over dallocx() is the removal of a metadata read, which often
242 suffers an L1 cache miss.
243 - Add missing header includes in jemalloc/jemalloc.h, so that applications
244 only have to #include <jemalloc/jemalloc.h>.
245 - Add support for additional platforms:
254 - Maintain dirty runs in per arena LRUs rather than in per arena trees of
255 dirty-run-containing chunks. In practice this change significantly reduces
256 dirty page purging volume.
257 - Integrate whole chunks into the unused dirty page purging machinery. This
258 reduces the cost of repeated huge allocation/deallocation, because it
259 effectively introduces a cache of chunks.
260 - Split the arena chunk map into two separate arrays, in order to increase
261 cache locality for the frequently accessed bits.
262 - Move small run metadata out of runs, into arena chunk headers. This reduces
263 run fragmentation, smaller runs reduce external fragmentation for small size
264 classes, and packed (less uniformly aligned) metadata layout improves CPU
265 cache set distribution.
266 - Randomly distribute large allocation base pointer alignment relative to page
267 boundaries in order to more uniformly utilize CPU cache sets. This can be
268 disabled via the --disable-cache-oblivious configure option, and queried via
269 the "config.cache_oblivious" mallctl.
270 - Micro-optimize the fast paths for the public API functions.
271 - Refactor thread-specific data to reside in a single structure. This assures
272 that only a single TLS read is necessary per call into the public API.
273 - Implement in-place huge allocation growing and shrinking.
274 - Refactor rtree (radix tree for chunk lookups) to be lock-free, and make
275 additional optimizations that reduce maximum lookup depth to one or two
276 levels. This resolves what was a concurrency bottleneck for per arena huge
277 allocation, because a global data structure is critical for determining
278 which arenas own which huge allocations.
280 Incompatible changes:
281 - Replace --enable-cc-silence with --disable-cc-silence to suppress spurious
283 - Assure that the constness of malloc_usable_size()'s return type matches that
284 of the system implementation.
285 - Change the heap profile dump format to support per thread heap profiling,
286 rename pprof to jeprof, and enhance it with the --thread=<n> option. As a
287 result, the bundled jeprof must now be used rather than the upstream
289 - Disable "opt.prof_final" by default, in order to avoid atexit(3), which can
290 internally deadlock on some platforms.
291 - Change the "arenas.nlruns" mallctl type from size_t to unsigned.
292 - Replace the "stats.arenas.<i>.bins.<j>.allocated" mallctl with
293 "stats.arenas.<i>.bins.<j>.curregs".
294 - Ignore MALLOC_CONF in set{uid,gid,cap} binaries.
295 - Ignore MALLOCX_ARENA(a) in dallocx(), in favor of using the
296 MALLOCX_TCACHE(tc) and MALLOCX_TCACHE_NONE flags to control tcache usage.
299 - Remove the *allocm() API, which is superseded by the *allocx() API.
300 - Remove the --enable-dss options, and make dss non-optional on all platforms
301 which support sbrk(2).
302 - Remove the "arenas.purge" mallctl, which was obsoleted by the
303 "arena.<i>.purge" mallctl in 3.1.0.
304 - Remove the unnecessary "opt.valgrind" mallctl; jemalloc automatically
305 detects whether it is running inside Valgrind.
306 - Remove the "stats.huge.allocated", "stats.huge.nmalloc", and
307 "stats.huge.ndalloc" mallctls.
308 - Remove the --enable-mremap option.
309 - Remove the "stats.chunks.current", "stats.chunks.total", and
310 "stats.chunks.high" mallctls.
313 - Fix the cactive statistic to decrease (rather than increase) when active
314 memory decreases. This regression was first released in 3.5.0.
315 - Fix OOM handling in memalign() and valloc(). A variant of this bug existed
316 in all releases since 2.0.0, which introduced these functions.
317 - Fix an OOM-related regression in arena_tcache_fill_small(), which could
318 cause cache corruption on OOM. This regression was present in all releases
319 from 2.2.0 through 3.6.0.
320 - Fix size class overflow handling for malloc(), posix_memalign(), memalign(),
321 calloc(), and realloc() when profiling is enabled.
322 - Fix the "arena.<i>.dss" mallctl to return an error if "primary" or
323 "secondary" precedence is specified, but sbrk(2) is not supported.
324 - Fix fallback lg_floor() implementations to handle extremely large inputs.
325 - Ensure the default purgeable zone is after the default zone on OS X.
326 - Fix latent bugs in atomic_*().
327 - Fix the "arena.<i>.dss" mallctl to handle read-only calls.
328 - Fix tls_model configuration to enable the initial-exec model when possible.
329 - Mark malloc_conf as a weak symbol so that the application can override it.
330 - Correctly detect glibc's adaptive pthread mutexes.
331 - Fix the --without-export configure option.
333 * 3.6.0 (March 31, 2014)
335 This version contains a critical bug fix for a regression present in 3.5.0 and
339 - Fix a regression in arena_chunk_alloc() that caused crashes during
340 small/large allocation if chunk allocation failed. In the absence of this
341 bug, chunk allocation failure would result in allocation failure, e.g. NULL
342 return from malloc(). This regression was introduced in 3.5.0.
343 - Fix backtracing for gcc intrinsics-based backtracing by specifying
344 -fno-omit-frame-pointer to gcc. Note that the application (and all the
345 libraries it links to) must also be compiled with this option for
346 backtracing to be reliable.
347 - Use dss allocation precedence for huge allocations as well as small/large
349 - Fix test assertion failure message formatting. This bug did not manifest on
350 x86_64 systems because of implementation subtleties in va_list.
351 - Fix inconsequential test failures for hash and SFMT code.
354 - Support heap profiling on FreeBSD. This feature depends on the proc
355 filesystem being mounted during heap profile dumping.
357 * 3.5.1 (February 25, 2014)
359 This version primarily addresses minor bugs in test code.
362 - Configure Solaris/Illumos to use MADV_FREE.
363 - Fix junk filling for mremap(2)-based huge reallocation. This is only
364 relevant if configuring with the --enable-mremap option specified.
365 - Avoid compilation failure if 'restrict' C99 keyword is not supported by the
367 - Add a configure test for SSE2 rather than assuming it is usable on i686
368 systems. This fixes test compilation errors, especially on 32-bit Linux
370 - Fix mallctl argument size mismatches (size_t vs. uint64_t) in the stats unit
372 - Fix/remove flawed alignment-related overflow tests.
373 - Prevent compiler optimizations that could change backtraces in the
374 prof_accum unit test.
376 * 3.5.0 (January 22, 2014)
378 This version focuses on refactoring and automated testing, though it also
379 includes some non-trivial heap profiling optimizations not mentioned below.
382 - Add the *allocx() API, which is a successor to the experimental *allocm()
383 API. The *allocx() functions are slightly simpler to use because they have
384 fewer parameters, they directly return the results of primary interest, and
385 mallocx()/rallocx() avoid the strict aliasing pitfall that
386 allocm()/rallocm() share with posix_memalign(). Note that *allocm() is
387 slated for removal in the next non-bugfix release.
388 - Add support for LinuxThreads.
391 - Unless heap profiling is enabled, disable floating point code and don't link
392 with libm. This, in combination with e.g. EXTRA_CFLAGS=-mno-sse on x64
393 systems, makes it possible to completely disable floating point register
394 use. Some versions of glibc neglect to save/restore caller-saved floating
395 point registers during dynamic lazy symbol loading, and the symbol loading
396 code uses whatever malloc the application happens to have linked/loaded
397 with, the result being potential floating point register corruption.
398 - Report ENOMEM rather than EINVAL if an OOM occurs during heap profiling
399 backtrace creation in imemalign(). This bug impacted posix_memalign() and
401 - Fix a file descriptor leak in a prof_dump_maps() error path.
402 - Fix prof_dump() to close the dump file descriptor for all relevant error
404 - Fix rallocm() to use the arena specified by the ALLOCM_ARENA(s) flag for
405 allocation, not just deallocation.
406 - Fix a data race for large allocation stats counters.
407 - Fix a potential infinite loop during thread exit. This bug occurred on
408 Solaris, and could affect other platforms with similar pthreads TSD
410 - Don't junk-fill reallocations unless usable size changes. This fixes a
411 violation of the *allocx()/*allocm() semantics.
412 - Fix growing large reallocation to junk fill new space.
413 - Fix huge deallocation to junk fill when munmap is disabled.
414 - Change the default private namespace prefix from empty to je_, and change
415 --with-private-namespace-prefix so that it prepends an additional prefix
416 rather than replacing je_. This reduces the likelihood of applications
417 which statically link jemalloc experiencing symbol name collisions.
418 - Add missing private namespace mangling (relevant when
419 --with-private-namespace is specified).
420 - Add and use JEMALLOC_INLINE_C so that static inline functions are marked as
421 static even for debug builds.
422 - Add a missing mutex unlock in a malloc_init_hard() error path. In practice
423 this error path is never executed.
424 - Fix numerous bugs in malloc_strotumax() error handling/reporting. These
425 bugs had no impact except for malformed inputs.
426 - Fix numerous bugs in malloc_snprintf(). These bugs were not exercised by
427 existing calls, so they had no impact.
429 * 3.4.1 (October 20, 2013)
432 - Fix a race in the "arenas.extend" mallctl that could cause memory corruption
433 of internal data structures and subsequent crashes.
434 - Fix Valgrind integration flaws that caused Valgrind warnings about reads of
435 uninitialized memory in:
436 + arena chunk headers
437 + internal zero-initialized data structures (relevant to tcache and prof
439 - Preserve errno during the first allocation. A readlink(2) call during
440 initialization fails unless /etc/malloc.conf exists, so errno was typically
441 set during the first allocation prior to this fix.
442 - Fix compilation warnings reported by gcc 4.8.1.
444 * 3.4.0 (June 2, 2013)
446 This version is essentially a small bugfix release, but the addition of
447 aarch64 support requires that the minor version be incremented.
450 - Fix race-triggered deadlocks in chunk_record(). These deadlocks were
451 typically triggered by multiple threads concurrently deallocating huge
455 - Add support for the aarch64 architecture.
457 * 3.3.1 (March 6, 2013)
459 This version fixes bugs that are typically encountered only when utilizing
460 custom run-time options.
463 - Fix a locking order bug that could cause deadlock during fork if heap
464 profiling were enabled.
465 - Fix a chunk recycling bug that could cause the allocator to lose track of
466 whether a chunk was zeroed. On FreeBSD, NetBSD, and OS X, it could cause
467 corruption if allocating via sbrk(2) (unlikely unless running with the
468 "dss:primary" option specified). This was completely harmless on Linux
469 unless using mlockall(2) (and unlikely even then, unless the
470 --disable-munmap configure option or the "dss:primary" option was
471 specified). This regression was introduced in 3.1.0 by the
472 mlockall(2)/madvise(2) interaction fix.
473 - Fix TLS-related memory corruption that could occur during thread exit if the
474 thread never allocated memory. Only the quarantine and prof facilities were
476 - Fix two quarantine bugs:
477 + Internal reallocation of the quarantined object array leaked the old
479 + Reallocation failure for internal reallocation of the quarantined object
480 array (very unlikely) resulted in memory corruption.
481 - Fix Valgrind integration to annotate all internally allocated memory in a
482 way that keeps Valgrind happy about internal data structure access.
483 - Fix building for s390 systems.
485 * 3.3.0 (January 23, 2013)
487 This version includes a few minor performance improvements in addition to the
488 listed new features and bug fixes.
491 - Add clipping support to lg_chunk option processing.
492 - Add the --enable-ivsalloc option.
493 - Add the --without-export option.
494 - Add the --disable-zone-allocator option.
497 - Fix "arenas.extend" mallctl to output the number of arenas.
498 - Fix chunk_recycle() to unconditionally inform Valgrind that returned memory
500 - Fix build break on FreeBSD related to alloca.h.
502 * 3.2.0 (November 9, 2012)
504 In addition to a couple of bug fixes, this version modifies page run
505 allocation and dirty page purging algorithms in order to better control
506 page-level virtual memory fragmentation.
508 Incompatible changes:
509 - Change the "opt.lg_dirty_mult" default from 5 to 3 (32:1 to 8:1).
512 - Fix dss/mmap allocation precedence code to use recyclable mmap memory only
513 after primary dss allocation fails.
514 - Fix deadlock in the "arenas.purge" mallctl. This regression was introduced
515 in 3.1.0 by the addition of the "arena.<i>.purge" mallctl.
517 * 3.1.0 (October 16, 2012)
520 - Auto-detect whether running inside Valgrind, thus removing the need to
521 manually specify MALLOC_CONF=valgrind:true.
522 - Add the "arenas.extend" mallctl, which allows applications to create
523 manually managed arenas.
524 - Add the ALLOCM_ARENA() flag for {,r,d}allocm().
525 - Add the "opt.dss", "arena.<i>.dss", and "stats.arenas.<i>.dss" mallctls,
526 which provide control over dss/mmap precedence.
527 - Add the "arena.<i>.purge" mallctl, which obsoletes "arenas.purge".
528 - Define LG_QUANTUM for hppa.
530 Incompatible changes:
531 - Disable tcache by default if running inside Valgrind, in order to avoid
532 making unallocated objects appear reachable to Valgrind.
533 - Drop const from malloc_usable_size() argument on Linux.
536 - Fix heap profiling crash if sampled object is freed via realloc(p, 0).
537 - Remove const from __*_hook variable declarations, so that glibc can modify
538 them during process forking.
539 - Fix mlockall(2)/madvise(2) interaction.
540 - Fix fork(2)-related deadlocks.
541 - Fix error return value for "thread.tcache.enabled" mallctl.
543 * 3.0.0 (May 11, 2012)
545 Although this version adds some major new features, the primary focus is on
546 internal code cleanup that facilitates maintainability and portability, most
547 of which is not reflected in the ChangeLog. This is the first release to
548 incorporate substantial contributions from numerous other developers, and the
549 result is a more broadly useful allocator (see the git revision history for
550 contribution details). Note that the license has been unified, thanks to
551 Facebook granting a license under the same terms as the other copyright
552 holders (see COPYING).
555 - Implement Valgrind support, redzones, and quarantine.
556 - Add support for additional platforms:
560 + Windows (no support yet for replacing the system malloc)
561 - Add support for additional architectures:
565 - Add support for cross compiling.
566 - Add nallocm(), which rounds a request size up to the nearest size class
567 without actually allocating.
568 - Implement aligned_alloc() (blame C11).
569 - Add the "thread.tcache.enabled" mallctl.
570 - Add the "opt.prof_final" mallctl.
571 - Update pprof (from gperftools 2.0).
572 - Add the --with-mangling option.
573 - Add the --disable-experimental option.
574 - Add the --disable-munmap option, and make it the default on Linux.
575 - Add the --enable-mremap option, which disables use of mremap(2) by default.
577 Incompatible changes:
578 - Enable stats by default.
579 - Enable fill by default.
580 - Disable lazy locking by default.
581 - Rename the "tcache.flush" mallctl to "thread.tcache.flush".
582 - Rename the "arenas.pagesize" mallctl to "arenas.page".
583 - Change the "opt.lg_prof_sample" default from 0 to 19 (1 B to 512 KiB).
584 - Change the "opt.prof_accum" default from true to false.
587 - Remove the swap feature, including the "config.swap", "swap.avail",
588 "swap.prezeroed", "swap.nfds", and "swap.fds" mallctls.
589 - Remove highruns statistics, including the
590 "stats.arenas.<i>.bins.<j>.highruns" and
591 "stats.arenas.<i>.lruns.<j>.highruns" mallctls.
592 - As part of small size class refactoring, remove the "opt.lg_[qc]space_max",
593 "arenas.cacheline", "arenas.subpage", "arenas.[tqcs]space_{min,max}", and
594 "arenas.[tqcs]bins" mallctls.
595 - Remove the "arenas.chunksize" mallctl.
596 - Remove the "opt.lg_prof_tcmax" option.
597 - Remove the "opt.lg_prof_bt_max" option.
598 - Remove the "opt.lg_tcache_gc_sweep" option.
599 - Remove the --disable-tiny option, including the "config.tiny" mallctl.
600 - Remove the --enable-dynamic-page-shift configure option.
601 - Remove the --enable-sysv configure option.
604 - Fix a statistics-related bug in the "thread.arena" mallctl that could cause
605 invalid statistics and crashes.
606 - Work around TLS deallocation via free() on Linux. This bug could cause
607 write-after-free memory corruption.
608 - Fix a potential deadlock that could occur during interval- and
609 growth-triggered heap profile dumps.
610 - Fix large calloc() zeroing bugs due to dropping chunk map unzeroed flags.
611 - Fix chunk_alloc_dss() to stop claiming memory is zeroed. This bug could
612 cause memory corruption and crashes with --enable-dss specified.
613 - Fix fork-related bugs that could cause deadlock in children between fork
615 - Fix malloc_stats_print() to honor 'b' and 'l' in the opts parameter.
616 - Fix realloc(p, 0) to act like free(p).
617 - Do not enforce minimum alignment in memalign().
618 - Check for NULL pointer in malloc_usable_size().
619 - Fix an off-by-one heap profile statistics bug that could be observed in
620 interval- and growth-triggered heap profiles.
621 - Fix the "epoch" mallctl to update cached stats even if the passed in epoch
623 - Fix bin->runcur management to fix a layout policy bug. This bug did not
625 - Fix a bug in choose_arena_hard() that potentially caused more arenas to be
626 initialized than necessary.
627 - Add missing "opt.lg_tcache_max" mallctl implementation.
628 - Use glibc allocator hooks to make mixed allocator usage less likely.
629 - Fix build issues for --disable-tcache.
630 - Don't mangle pthread_create() when --with-private-namespace is specified.
632 * 2.2.5 (November 14, 2011)
635 - Fix huge_ralloc() race when using mremap(2). This is a serious bug that
636 could cause memory corruption and/or crashes.
637 - Fix huge_ralloc() to maintain chunk statistics.
638 - Fix malloc_stats_print(..., "a") output.
640 * 2.2.4 (November 5, 2011)
643 - Initialize arenas_tsd before using it. This bug existed for 2.2.[0-3], as
644 well as for --disable-tls builds in earlier releases.
645 - Do not assume a 4 KiB page size in test/rallocm.c.
647 * 2.2.3 (August 31, 2011)
649 This version fixes numerous bugs related to heap profiling.
652 - Fix a prof-related race condition. This bug could cause memory corruption,
653 but only occurred in non-default configurations (prof_accum:false).
654 - Fix off-by-one backtracing issues (make sure that prof_alloc_prep() is
655 excluded from backtraces).
656 - Fix a prof-related bug in realloc() (only triggered by OOM errors).
657 - Fix prof-related bugs in allocm() and rallocm().
658 - Fix prof_tdata_cleanup() for --disable-tls builds.
659 - Fix a relative include path, to fix objdir builds.
661 * 2.2.2 (July 30, 2011)
664 - Fix a build error for --disable-tcache.
665 - Fix assertions in arena_purge() (for real this time).
666 - Add the --with-private-namespace option. This is a workaround for symbol
667 conflicts that can inadvertently arise when using static libraries.
669 * 2.2.1 (March 30, 2011)
672 - Implement atomic operations for x86/x64. This fixes compilation failures
673 for versions of gcc that are still in wide use.
674 - Fix an assertion in arena_purge().
676 * 2.2.0 (March 22, 2011)
678 This version incorporates several improvements to algorithms and data
679 structures that tend to reduce fragmentation and increase speed.
682 - Add the "stats.cactive" mallctl.
683 - Update pprof (from google-perftools 1.7).
684 - Improve backtracing-related configuration logic, and add the
685 --disable-prof-libgcc option.
688 - Change default symbol visibility from "internal", to "hidden", which
689 decreases the overhead of library-internal function calls.
690 - Fix symbol visibility so that it is also set on OS X.
691 - Fix a build dependency regression caused by the introduction of the .pic.o
692 suffix for PIC object files.
693 - Add missing checks for mutex initialization failures.
694 - Don't use libgcc-based backtracing except on x64, where it is known to work.
695 - Fix deadlocks on OS X that were due to memory allocation in
696 pthread_mutex_lock().
697 - Heap profiling-specific fixes:
698 + Fix memory corruption due to integer overflow in small region index
699 computation, when using a small enough sample interval that profiling
700 context pointers are stored in small run headers.
701 + Fix a bootstrap ordering bug that only occurred with TLS disabled.
702 + Fix a rallocm() rsize bug.
703 + Fix error detection bugs for aligned memory allocation.
705 * 2.1.3 (March 14, 2011)
708 - Fix a cpp logic regression (due to the "thread.{de,}allocatedp" mallctl fix
710 - Fix a "thread.arena" mallctl bug.
711 - Fix a thread cache stats merging bug.
713 * 2.1.2 (March 2, 2011)
716 - Fix "thread.{de,}allocatedp" mallctl for OS X.
717 - Add missing jemalloc.a to build system.
719 * 2.1.1 (January 31, 2011)
722 - Fix aligned huge reallocation (affected allocm()).
723 - Fix the ALLOCM_LG_ALIGN macro definition.
724 - Fix a heap dumping deadlock.
725 - Fix a "thread.arena" mallctl bug.
727 * 2.1.0 (December 3, 2010)
729 This version incorporates some optimizations that can't quite be considered
733 - Use Linux's mremap(2) for huge object reallocation when possible.
734 - Avoid locking in mallctl*() when possible.
735 - Add the "thread.[de]allocatedp" mallctl's.
736 - Convert the manual page source from roff to DocBook, and generate both roff
740 - Fix a crash due to incorrect bootstrap ordering. This only impacted
741 --enable-debug --enable-dss configurations.
742 - Fix a minor statistics bug for mallctl("swap.avail", ...).
744 * 2.0.1 (October 29, 2010)
747 - Fix a race condition in heap profiling that could cause undefined behavior
748 if "opt.prof_accum" were disabled.
749 - Add missing mutex unlocks for some OOM error paths in the heap profiling
751 - Fix a compilation error for non-C99 builds.
753 * 2.0.0 (October 24, 2010)
755 This version focuses on the experimental *allocm() API, and on improved
756 run-time configuration/introspection. Nonetheless, numerous performance
757 improvements are also included.
760 - Implement the experimental {,r,s,d}allocm() API, which provides a superset
761 of the functionality available via malloc(), calloc(), posix_memalign(),
762 realloc(), malloc_usable_size(), and free(). These functions can be used to
763 allocate/reallocate aligned zeroed memory, ask for optional extra memory
764 during reallocation, prevent object movement during reallocation, etc.
765 - Replace JEMALLOC_OPTIONS/JEMALLOC_PROF_PREFIX with MALLOC_CONF, which is
766 more human-readable, and more flexible. For example:
769 MALLOC_CONF=abort:true,fill:true,stats_print:true
770 - Port to Apple OS X. Sponsored by Mozilla.
771 - Make it possible for the application to control thread-->arena mappings via
772 the "thread.arena" mallctl.
773 - Add compile-time support for all TLS-related functionality via pthreads TSD.
774 This is mainly of interest for OS X, which does not support TLS, but has a
775 TSD implementation with similar performance.
776 - Override memalign() and valloc() if they are provided by the system.
777 - Add the "arenas.purge" mallctl, which can be used to synchronously purge all
779 - Make cumulative heap profiling data optional, so that it is possible to
780 limit the amount of memory consumed by heap profiling data structures.
781 - Add per thread allocation counters that can be accessed via the
782 "thread.allocated" and "thread.deallocated" mallctls.
784 Incompatible changes:
785 - Remove JEMALLOC_OPTIONS and malloc_options (see MALLOC_CONF above).
786 - Increase default backtrace depth from 4 to 128 for heap profiling.
787 - Disable interval-based profile dumps by default.
790 - Remove bad assertions in fork handler functions. These assertions could
791 cause aborts for some combinations of configure settings.
792 - Fix strerror_r() usage to deal with non-standard semantics in GNU libc.
793 - Fix leak context reporting. This bug tended to cause the number of contexts
794 to be underreported (though the reported number of objects and bytes were
796 - Fix a realloc() bug for large in-place growing reallocation. This bug could
797 cause memory corruption, but it was hard to trigger.
798 - Fix an allocation bug for small allocations that could be triggered if
799 multiple threads raced to create a new run of backing pages.
800 - Enhance the heap profiler to trigger samples based on usable size, rather
802 - Fix a heap profiling bug due to sometimes losing track of requested object
803 size for sampled objects.
805 * 1.0.3 (August 12, 2010)
808 - Fix the libunwind-based implementation of stack backtracing (used for heap
809 profiling). This bug could cause zero-length backtraces to be reported.
810 - Add a missing mutex unlock in library initialization code. If multiple
811 threads raced to initialize malloc, some of them could end up permanently
814 * 1.0.2 (May 11, 2010)
817 - Fix junk filling of large objects, which could cause memory corruption.
818 - Add MAP_NORESERVE support for chunk mapping, because otherwise virtual
819 memory limits could cause swap file configuration to fail. Contributed by
822 * 1.0.1 (April 14, 2010)
825 - Fix compilation when --enable-fill is specified.
826 - Fix threads-related profiling bugs that affected accuracy and caused memory
827 to be leaked during thread exit.
828 - Fix dirty page purging race conditions that could cause crashes.
829 - Fix crash in tcache flushing code during thread destruction.
831 * 1.0.0 (April 11, 2010)
833 This release focuses on speed and run-time introspection. Numerous
834 algorithmic improvements make this release substantially faster than its
838 - Implement autoconf-based configuration system.
839 - Add mallctl*(), for the purposes of introspection and run-time
841 - Make it possible for the application to manually flush a thread's cache, via
842 the "tcache.flush" mallctl.
843 - Base maximum dirty page count on proportion of active memory.
844 - Compute various additional run-time statistics, including per size class
845 statistics for large objects.
846 - Expose malloc_stats_print(), which can be called repeatedly by the
848 - Simplify the malloc_message() signature to only take one string argument,
849 and incorporate an opaque data pointer argument for use by the application
850 in combination with malloc_stats_print().
851 - Add support for allocation backed by one or more swap files, and allow the
852 application to disable over-commit if swap files are in use.
853 - Implement allocation profiling and leak checking.
856 - Remove the dynamic arena rebalancing code, since thread-specific caching
860 - Modify chunk allocation to work when address space layout randomization
862 - Fix thread cleanup bugs related to TLS destruction.
863 - Handle 0-size allocation requests in posix_memalign().
864 - Fix a chunk leak. The leaked chunks were never touched, so this impacted
865 virtual memory usage, but not physical memory usage.
867 * linux_2008082[78]a (August 27/28, 2008)
869 These snapshot releases are the simple result of incorporating Linux-specific
870 support into the FreeBSD malloc sources.
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