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.
In practice this bug had limited impact (and then only by increasing
chunk fragmentation) because run_quantize_ceil() returned correct
results except for inputs that could only arise from aligned allocation
requests that required more than page alignment.
This bug existed in the original run quantization implementation, which
was introduced by 8a03cf039c (Implement
cache index randomization for large allocations.).
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.
When using LinuxThreads, malloc bootstrapping deadlocks, since
malloc_tsd_boot0() ends up calling pthread_setspecific(), which causes
recursive allocation. Fix it by moving the malloc_tsd_boot0() call to
malloc_init_hard_recursible().
The deadlock was introduced by 8bb3198f72
(Refactor/fix arenas manipulation.), when tsd_boot() was split and the
top half, tsd_boot0(), got an extra tsd_wrapper_set() call.
- Combine multiple runtime branches into a single malloc_slow check.
- Avoid calling arena_choose / size2index / index2size on fast path.
- A few micro optimizations.
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.).
Zero all trailing bytes of large allocations when
--enable-cache-oblivious configure option is enabled. This regression
was introduced by 8a03cf039c (Implement
cache index randomization for large allocations.).
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. Prior to this fix, spurious entries with
arbitrary object/byte counts could appear in heap profiles, which
resulted in jeprof inaccuracies or failures.
Simplify imallocx_prof_sample() to always operate on usize rather than
sometimes using size. This avoids redundant usize computations and
more closely fits the style adopted by i[rx]allocx_prof_sample() to fix
sampling bugs.
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.
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().)
