Commit Graph

3072 Commits

Author SHA1 Message Date
Qi Wang
9ed84b0d45 Add init function support to tsd members.
This will facilitate embedding tcache into tsd, which will require proper
initialization cannot be done via the static initializer.  Make tsd->rtree_ctx
to be initialized via rtree_ctx_data_init().
2017-04-04 00:19:21 -07:00
Aliaksey Kandratsenka
5bf800a542 issue-586: detect main executable even if PIE is active
Previous logic of detecting main program addresses is to assume that
main executable is at least addressess. With PIE (active by default on
Ubuntus) it doesn't work.

In order to deal with that, we're attempting to find main executable
mapping in /proc/[pid]/maps. And old logic is preserved too just in
case.
2017-04-03 19:02:51 -07:00
Qi Wang
d4e98bc0b2 Lookup extent once per time during tcache_flush_small / _large.
Caching the extents on stack to avoid redundant looking up overhead.
2017-03-28 09:58:25 -07:00
Jason Evans
07f4f93434 Move arena_slab_data_t's nfree into extent_t's e_bits.
Compact extent_t to 128 bytes on 64-bit systems by moving
arena_slab_data_t's nfree into extent_t's e_bits.

Cacheline-align extent_t structures so that they always cross the
minimum number of cacheline boundaries.

Re-order extent_t fields such that all fields except the slab bitmap
(and overlaid heap profiling context pointer) are in the first
cacheline.

This resolves #461.
2017-03-27 22:43:39 -07:00
Qi Wang
af3d737a9a Simplify rtree cache replacement policy.
To avoid memmove on free() fast path, simplify the cache replacement policy to
only bubble up the cache hit element by 1.
2017-03-27 13:42:31 -07:00
Jason Evans
c6d1819e48 Simplify rtree_clear() to avoid locking. 2017-03-27 13:22:52 -07:00
Jason Evans
4020523f67 Fix a race in rtree_szind_slab_update() for RTREE_LEAF_COMPACT. 2017-03-27 13:22:36 -07:00
Jason Evans
7c00f04ff4 Remove BITMAP_USE_TREE.
Remove tree-structured bitmap support, in order to reduce complexity and
ease maintenance.  No bitmaps larger than 512 bits have been necessary
since before 4.0.0, and there is no current plan that would increase
maximum bitmap size.  Although tree-structured bitmaps were used on
32-bit platforms prior to this change, the overall benefits were
questionable (higher metadata overhead, higher bitmap modification cost,
marginally lower search cost).
2017-03-27 12:18:40 -07:00
Jason Evans
6258176c87 Fix bitmap_ffu() to work with 3+ levels. 2017-03-27 12:18:40 -07:00
Jason Evans
735ad8210c Pack various extent_t fields into a bitfield.
This reduces sizeof(extent_t) from 160 to 136 on x64.
2017-03-25 23:30:13 -07:00
Jason Evans
0591c204b4 Store arena index rather than (arena_t *) in extent_t. 2017-03-25 23:30:13 -07:00
Jason Evans
5e12223925 Fix BITMAP_USE_TREE version of bitmap_ffu().
This fixes an extent searching regression on 32-bit systems, caused by
the initial bitmap_ffu() implementation in
c8021d01f6 (Implement bitmap_ffu(), which
finds the first unset bit.), as first used in
5d33233a5e (Use a bitmap in extents_t to
speed up search.).
2017-03-25 23:29:32 -07:00
Qi Wang
e6b074472e Force inline ifree to avoid function call costs on fast path.
Without ALWAYS_INLINE, sometimes ifree() gets compiled into its own function,
which adds overhead on the fast path.
2017-03-24 17:54:28 -07:00
Jason Evans
5d33233a5e Use a bitmap in extents_t to speed up search.
Rather than iteratively checking all sufficiently large heaps during
search, maintain and use a bitmap in order to skip empty heaps.
2017-03-24 17:52:46 -07:00
Jason Evans
57e353163f Implement BITMAP_GROUPS(). 2017-03-24 17:52:46 -07:00
Jason Evans
c8021d01f6 Implement bitmap_ffu(), which finds the first unset bit. 2017-03-24 17:52:46 -07:00
Jason Evans
a832ebaee9 Use first fit layout policy instead of best fit.
For extents which do not delay coalescing, use first fit layout policy
rather than first-best fit layout policy.  This packs extents toward
older virtual memory mappings, but at the cost of higher search overhead
in the common case.

This resolves #711.
2017-03-24 17:52:46 -07:00
Qi Wang
bbc16a50f9 Added documentation for mutex profiling related mallctls. 2017-03-23 00:03:28 -07:00
Qi Wang
362e356675 Profile per arena base mutex, instead of just a0. 2017-03-23 00:03:28 -07:00
Qi Wang
d3fde1c124 Refactor mutex profiling code with x-macros. 2017-03-23 00:03:28 -07:00
Qi Wang
f6698ec1e6 Switch to nstime_t for the time related fields in mutex profiling. 2017-03-23 00:03:28 -07:00
Qi Wang
74f78cafda Added custom mutex spin.
A fixed max spin count is used -- with benchmark results showing it
solves almost all problems. As the benchmark used was rather intense,
the upper bound could be a little bit high. However it should offer a
good tradeoff between spinning and blocking.
2017-03-23 00:03:28 -07:00
Qi Wang
20b8c70e9f Added extents_dirty / _muzzy mutexes, as well as decay_dirty / _muzzy. 2017-03-23 00:03:28 -07:00
Qi Wang
64c5f5c174 Added "stats.mutexes.reset" mallctl to reset all mutex stats.
Also switched from the term "lock" to "mutex".
2017-03-23 00:03:28 -07:00
Qi Wang
bd2006a41b Added JSON output for lock stats.
Also added option 'x' to malloc_stats() to bypass lock section.
2017-03-23 00:03:28 -07:00
Qi Wang
ca9074deff Added lock profiling and output for global locks (ctl, prof and base). 2017-03-23 00:03:28 -07:00
Qi Wang
0fb5c0e853 Add arena lock stats output. 2017-03-23 00:03:28 -07:00
Qi Wang
a4f176af57 Output bin lock profiling results to malloc_stats.
Two counters are included for the small bins: lock contention rate, and
max lock waiting time.
2017-03-23 00:03:28 -07:00
Qi Wang
6309df628f First stage of mutex profiling.
Switched to trylock and update counters based on state.
2017-03-23 00:03:28 -07:00
Jason Evans
32e7cf51cd Further specialize arena_[s]dalloc() tcache fast path.
Use tsd_rtree_ctx() rather than tsdn_rtree_ctx() when tcache is
non-NULL, in order to avoid an extra branch (and potentially extra stack
space) in the fast path.
2017-03-22 18:33:32 -07:00
Jason Evans
5e67fbc367 Push down iealloc() calls.
Call iealloc() as deep into call chains as possible without causing
redundant calls.
2017-03-22 18:33:32 -07:00
Jason Evans
51a2ec92a1 Remove extent dereferences from the deallocation fast paths. 2017-03-22 18:33:32 -07:00
Jason Evans
4f341412e5 Remove extent arg from isalloc() and arena_salloc(). 2017-03-22 18:33:32 -07:00
Jason Evans
0ee0e0c155 Implement compact rtree leaf element representation.
If a single virtual adddress pointer has enough unused bits to pack
{szind_t, extent_t *, bool, bool}, use a single pointer-sized field in
each rtree leaf element, rather than using three separate fields.  This
has little impact on access speed (fewer loads/stores, but more bit
twiddling), except that denser representation increases TLB
effectiveness.
2017-03-22 18:33:32 -07:00
Jason Evans
ce41ab0c57 Embed root node into rtree_t.
This avoids one atomic operation per tree access.
2017-03-22 18:33:32 -07:00
Jason Evans
99d68445ef Incorporate szind/slab into rtree leaves.
Expand and restructure the rtree API such that all common operations can
be achieved with minimal work, regardless of whether the rtree leaf
fields are independent versus packed into a single atomic pointer.
2017-03-22 18:33:32 -07:00
Jason Evans
944c8a3383 Split rtree_elm_t into rtree_{node,leaf}_elm_t.
This allows leaf elements to differ in size from internal node elements.

In principle it would be more correct to use a different type for each
level of the tree, but due to implementation details related to atomic
operations, we use casts anyway, thus counteracting the value of
additional type correctness.  Furthermore, such a scheme would require
function code generation (via cpp macros), as well as either unwieldy
type names for leaves or type aliases, e.g.

  typedef struct rtree_elm_d2_s rtree_leaf_elm_t;

This alternate strategy would be more correct, and with less code
duplication, but probably not worth the complexity.
2017-03-22 18:33:32 -07:00
Jason Evans
f50d6009fe Remove binind field from arena_slab_data_t.
binind is now redundant; the containing extent_t's szind field always
provides the same value.
2017-03-22 18:33:32 -07:00
Jason Evans
e8921cf2eb Convert extent_t's usize to szind.
Rather than storing usize only for large (and prof-promoted)
allocations, store the size class index for allocations that reside
within the extent, such that the size class index is valid for all
extents that contain extant allocations, and invalid otherwise (mainly
to make debugging simpler).
2017-03-22 18:33:32 -07:00
Jason Evans
bda12bd925 Clamp LG_VADDR for 32-bit builds on x64. 2017-03-22 18:33:32 -07:00
Qi Wang
ad91762635 Not re-binding iarena when migrate between arenas. 2017-03-21 14:05:20 -07:00
Jason Evans
3a1363bcf8 Refactor tcaches flush/destroy to reduce lock duration.
Drop tcaches_mtx before calling tcache_destroy().
2017-03-16 08:59:58 -07:00
Jason Evans
afb46ce236 Propagate madvise() success/failure from pages_purge_lazy(). 2017-03-16 08:44:57 -07:00
Jason Evans
64e458f5cd Implement two-phase decay-based purging.
Split decay-based purging into two phases, the first of which uses lazy
purging to convert dirty pages to "muzzy", and the second of which uses
forced purging, decommit, or unmapping to convert pages to clean or
destroy them altogether.  Not all operating systems support lazy
purging, yet the application may provide extent hooks that implement
lazy purging, so care must be taken to dynamically omit the first phase
when necessary.

The mallctl interfaces change as follows:
- opt.decay_time --> opt.{dirty,muzzy}_decay_time
- arena.<i>.decay_time --> arena.<i>.{dirty,muzzy}_decay_time
- arenas.decay_time --> arenas.{dirty,muzzy}_decay_time
- stats.arenas.<i>.pdirty --> stats.arenas.<i>.p{dirty,muzzy}
- stats.arenas.<i>.{npurge,nmadvise,purged} -->
  stats.arenas.<i>.{dirty,muzzy}_{npurge,nmadvise,purged}

This resolves #521.
2017-03-15 13:13:47 -07:00
Jason Evans
38a5bfc816 Move arena_t's purging field into arena_decay_t. 2017-03-15 13:13:47 -07:00
Jason Evans
765edd67b4 Refactor decay-related function parametrization.
Refactor most of the decay-related functions to take as parameters the
decay_t and associated extents_t structures to operate on.  This
prepares for supporting both lazy and forced purging on different decay
schedules.
2017-03-15 13:13:47 -07:00
David Goldblatt
ee202efc79 Convert remaining arena_stats_t fields to atomics
These were all size_ts, so we have atomics support for them on all platforms, so
the conversion is straightforward.

Left non-atomic is curlextents, which AFAICT is not used atomically anywhere.
2017-03-13 18:22:33 -07:00
David Goldblatt
4fc2acf5ae Switch atomic uint64_ts in arena_stats_t to C11 atomics
I expect this to be the trickiest conversion we will see, since we want atomics
on 64-bit platforms, but are also always able to piggyback on some sort of
external synchronization on non-64 bit platforms.
2017-03-13 18:22:33 -07:00
Jason Evans
26d23da6cd Prefer pages_purge_forced() over memset().
This has the dual advantages of allowing for sparsely used large
allocations, and relying on the kernel to supply zeroed pages, which
tends to be very fast on modern systems.
2017-03-13 18:19:57 -07:00
Jason Evans
28078274c4 Add alignment/size assertions to pages_*().
These sanity checks prevent what otherwise might result in failed system
calls and unintended fallback execution paths.
2017-03-13 18:19:57 -07:00