Refactor the arenas array, which contains pointers to all extant arenas,
such that it starts out as a sparse array of maximum size, and use
double-checked atomics-based reads as the basis for fast and simple
arena_get(). Additionally, reduce arenas_lock's role such that it only
protects against arena initalization races. These changes remove the
possibility for arena lookups to trigger locking, which resolves at
least one known (fork-related) deadlock.
This resolves#315.
Attempt mmap-based in-place huge reallocation by plumbing new_addr into
chunk_alloc_mmap(). This can dramatically speed up incremental huge
reallocation.
This resolves#335.
Separate run trees by index, replacing the previous quantize logic.
Quantization by index is now performed only on insertion / removal from
the tree, and not on node comparison, saving some cpu. This also means
we don't have to dereference the miscelm* pointers, saving half of the
memory loads from miscelms/mapbits that have fallen out of cache. A
linear scan of the indicies appears to be fast enough.
The only cost of this is an extra tree array in each arena.
Use a single uint64_t in nstime_t to store nanoseconds rather than using
struct timespec. This reduces fragility around conversions between long
and uint64_t, especially missing casts that only cause problems on
32-bit platforms.
This is an alternative to the existing ratio-based unused dirty page
purging, and is intended to eventually become the sole purging
mechanism.
Add mallctls:
- opt.purge
- opt.decay_time
- arena.<i>.decay
- arena.<i>.decay_time
- arenas.decay_time
- stats.arenas.<i>.decay_time
This resolves#325.
- Combine multiple runtime branches into a single malloc_slow check.
- Avoid calling arena_choose / size2index / index2size on fast path.
- A few micro optimizations.
ex_destroy iterates over the tree using post-order traversal so nodes
can be removed and processed by the callback function without paying the
cost to rebalance the tree. The destruction process cannot be stopped
once started.
clang-cl, an MSVC-compatible frontend built on top of clang, defined
_MSC_VER *and* supports __attribute__ syntax. The ordering of the
checks in jemalloc_macros.h.in, however, do the wrong thing for
clang-cl, as we want the Windows-specific macro definitions for
clang-cl. To support this use case, we reorder the checks so that
_MSC_VER is checked first (which includes clang-cl), and then
JEMALLOC_HAVE_ATTR) is checked. No functionality change intended.
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. This addresses a
special case missed in d260f442ce (Fix
xallocx(..., MALLOCX_ZERO) bugs.).
Don't assume Bourne shell is in /bin/sh when running size_classes.sh .
Consider __sparcv9 a synonym for __sparc64__ when defining LG_QUANTUM.
This resolves#275.
Add arena_prof_tctx_reset() and use it instead of arena_prof_tctx_set()
when resetting the tctx pointer during reallocation, which happens
whenever an originally sampled reallocated object is not sampled during
reallocation.
This regression was introduced by
594c759f37 (Optimize
arena_prof_tctx_set().)
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.
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.
