diff options
Diffstat (limited to 'dep/jemalloc/ChangeLog')
| -rw-r--r-- | dep/jemalloc/ChangeLog | 262 |
1 files changed, 257 insertions, 5 deletions
diff --git a/dep/jemalloc/ChangeLog b/dep/jemalloc/ChangeLog index d56ee999e69..8ed42cbeadb 100644 --- a/dep/jemalloc/ChangeLog +++ b/dep/jemalloc/ChangeLog @@ -1,10 +1,262 @@ Following are change highlights associated with official releases. Important -bug fixes are all mentioned, but internal enhancements are omitted here for -brevity (even though they are more fun to write about). Much more detail can be -found in the git revision history: +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 +* 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 disovering 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 @@ -21,7 +273,7 @@ found in the git revision history: 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 manifect on + - 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. @@ -516,7 +768,7 @@ found in the git revision history: - 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 addtional run-time statistics, including per size class + - 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. |