Commit Graph

582 Commits

Author SHA1 Message Date
Jason Evans
cc75c35db5 Add any() and remove_any() to ph.
These functions select the easiest-to-remove element in the heap, which
is either the most recently inserted aux list element or the root.  If
no calls are made to first() or remove_first(), the behavior (and time
complexity) is the same as for a LIFO queue.
2017-03-07 10:25:33 -08:00
Jason Evans
e201e24904 Perform delayed coalescing prior to purging.
Rather than purging uncoalesced extents, perform just enough incremental
coalescing to purge only fully coalesced extents.  In the absence of
cached extent reuse, the immediate versus delayed incremental purging
algorithms result in the same purge order.

This resolves #655.
2017-03-07 10:25:12 -08:00
David Goldblatt
4f1e94658a Change arena to use the atomic functions for ssize_t instead of the union strategy 2017-03-06 18:49:19 -08:00
David Goldblatt
438efede78 Add atomic types for ssize_t 2017-03-06 18:49:19 -08:00
David Goldblatt
424e3428b1 Make type abbreviations consistent: ssize_t is zd everywhere 2017-03-06 18:49:19 -08:00
David Goldblatt
84326c566a Insert not_reached after an exhaustive switch
In the C11 atomics backport, we couldn't use not_reached() in
atomic_enum_to_builtin (in atomic_gcc_atomic.h), since atomic.h was hermetic and
assert.h wasn't; there was a dependency issue.  assert.h is hermetic now, so we
can include it.
2017-03-06 15:08:43 -08:00
David Goldblatt
e9852b5776 Disentangle assert and util
This is the first header refactoring diff, #533.  It splits the assert and util
components into separate, hermetic, header files.  In the process, it splits out
two of the large sub-components of util (the stdio.h replacement, and bit
manipulation routines) into their own components (malloc_io.h and bit_util.h).
This is mostly to break up cyclic dependencies, but it also breaks off a good
chunk of the catch-all-ness of util, which is nice.
2017-03-06 15:08:43 -08:00
Jason Evans
04d8fcb745 Optimize malloc_large_stats_t maintenance.
Convert the nrequests field to be partially derived, and the curlextents
to be fully derived, in order to reduce the number of stats updates
needed during common operations.

This change affects ndalloc stats during arena reset, because it is no
longer possible to cancel out ndalloc effects (curlextents would become
negative).
2017-03-04 08:18:31 -08:00
David Goldblatt
d4ac7582f3 Introduce a backport of C11 atomics
This introduces a backport of C11 atomics.  It has four implementations; ranked
in order of preference, they are:
- GCC/Clang __atomic builtins
- GCC/Clang __sync builtins
- MSVC _Interlocked builtins
- C11 atomics, from <stdatomic.h>

The primary advantages are:
- Close adherence to the standard API gives us a defined memory model.
- Type safety: atomic objects are now separate types from non-atomic ones, so
  that it's impossible to mix up atomic and non-atomic updates (which is
  undefined behavior that compilers are starting to take advantage of).
- Efficiency: we can specify ordering for operations, avoiding fences and
  atomic operations on strongly ordered architectures (example:
  `atomic_write_u32(ptr, val);` involves a CAS loop, whereas
  `atomic_store(ptr, val, ATOMIC_RELEASE);` is a plain store.

This diff leaves in the current atomics API (implementing them in terms of the
backport).  This lets us transition uses over piecemeal.

Testing:
This is by nature hard to test. I've manually tested the first three options on
Linux on gcc by futzing with the #defines manually, on freebsd with gcc and
clang, on MSVC, and on OS X with clang.  All of these were x86 machines though,
and we don't have any test infrastructure set up for non-x86 platforms.
2017-03-03 13:40:59 -08:00
David Goldblatt
957b8c5f21 Stop #define-ining away 'inline'
In the long term, we'll transition to C99-style inline semantics.  In the
short-term, this will allow both styles to coexist without breaking one another.
2017-03-03 13:40:59 -08:00
Jason Evans
fd058f572b Immediately purge cached extents if decay_time is 0.
This fixes a regression caused by
54269dc0ed (Remove obsolete
arena_maybe_purge() call.), as well as providing a general fix.

This resolves #665.
2017-03-02 19:43:06 -08:00
Jason Evans
d61a5f76b2 Convert arena_decay_t's time to be atomically synchronized. 2017-03-02 19:43:06 -08:00
Jason Evans
472fef2e12 Fix {allocated,nmalloc,ndalloc,nrequests}_large stats regression.
This fixes a regression introduced by
d433471f58 (Derive
{allocated,nmalloc,ndalloc,nrequests}_large stats.).
2017-02-27 11:18:07 -08:00
Jason Evans
079b8bee37 Tidy up extent quantization.
Remove obsolete unit test scaffolding for extent quantization.  Remove
redundant assertions.  Add an assertion to
extents_first_best_fit_locked() that should help prevent aligned
allocation regressions.
2017-02-27 11:17:47 -08:00
Jason Evans
d727596bcb Update a comment. 2017-02-26 11:05:27 -08:00
Qi Wang
c2323e13a5 Get rid of witness in malloc_mutex_t when !(configured w/ debug).
We don't touch witness at all when config_debug == false.  Let's only pay the
memory cost in malloc_mutex_s when needed. Note that when !config_debug, we keep
the field in a union so that we don't have to do #ifdefs in multiple places.
2017-02-24 09:41:29 -08:00
Jason Evans
8ac7937eb5 Remove remainder of mb (memory barrier).
This complements 94c5d22a4d (Remove mb.h,
which is unused).
2017-02-22 00:24:14 -08:00
Jason Evans
003ca8717f Move arena_basic_stats_merge() prototype (hygienic cleanup). 2017-02-21 12:46:20 -08:00
Jason Evans
2dfc5b5aac Disable coalescing of cached extents.
Extent splitting and coalescing is a major component of large allocation
overhead, and disabling coalescing of cached extents provides a simple
and effective hysteresis mechanism.  Once two-phase purging is
implemented, it will probably make sense to leave coalescing disabled
for the first phase, but coalesce during the second phase.
2017-02-16 20:11:50 -08:00
Jason Evans
b0654b95ed Fix arena->stats.mapped accounting.
Mapped memory increases when extent_alloc_wrapper() succeeds, and
decreases when extent_dalloc_wrapper() is called (during purging).
2017-02-16 15:52:11 -08:00
Jason Evans
f8fee6908d Synchronize arena->decay with arena->decay.mtx.
This removes the last use of arena->lock.
2017-02-16 09:39:46 -08:00
Jason Evans
d433471f58 Derive {allocated,nmalloc,ndalloc,nrequests}_large stats.
This mildly reduces stats update overhead during normal operation.
2017-02-16 09:39:46 -08:00
Jason Evans
ab25d3c987 Synchronize arena->tcache_ql with arena->tcache_ql_mtx.
This replaces arena->lock synchronization.
2017-02-16 09:39:46 -08:00
Jason Evans
6b5cba4191 Convert arena->stats synchronization to atomics. 2017-02-16 09:39:46 -08:00
Jason Evans
fa2d64c94b Convert arena->prof_accumbytes synchronization to atomics. 2017-02-16 09:39:46 -08:00
Jason Evans
b779522b9b Convert arena->dss_prec synchronization to atomics. 2017-02-16 09:39:46 -08:00
Jason Evans
0721b895ff Do not generate unused tsd_*_[gs]et() functions.
This avoids a gcc diagnostic note:
    note: The ABI for passing parameters with 64-byte alignment has
    changed in GCC 4.6
This note related to the cacheline alignment of rtree_ctx_t, which was
introduced by 4a346f5593 (Replace rtree
path cache with LRU cache.).
2017-02-13 10:47:16 -08:00
Jason Evans
6b8ef771a9 Fix rtree_subkey() regression.
Fix rtree_subkey() to use uintptr_t rather than unsigned for key
bitmasking.  This regression was introduced by
4a346f5593 (Replace rtree path cache with
LRU cache.).
2017-02-10 09:05:02 -08:00
Jason Evans
7f55dbef9b Enable mutex witnesses even when !isthreaded.
This fixes interactions with witness_assert_depth[_to_rank](), which was
added in d0e93ada51 (Add
witness_assert_depth[_to_rank]().).
2017-02-09 17:05:47 -08:00
Jason Evans
db7da56359 Spin adaptively in rtree_elm_acquire(). 2017-02-08 18:50:03 -08:00
Jason Evans
de8a68e853 Enhance spin_adaptive() to yield after several iterations.
This avoids worst case behavior if e.g. another thread is preempted
while owning the resource the spinning thread is waiting for.
2017-02-08 18:50:03 -08:00
Jason Evans
5f11830754 Replace spin_init() with SPIN_INITIALIZER. 2017-02-08 18:50:03 -08:00
Jason Evans
650c070e10 Remove rtree support for 0 (NULL) keys.
NULL can never actually be inserted in practice, and removing support
allows a branch to be removed from the fast path.
2017-02-08 18:50:03 -08:00
Jason Evans
f5cf9b19c8 Determine rtree levels at compile time.
Rather than dynamically building a table to aid per level computations,
define a constant table at compile time.  Omit both high and low
insignificant bits.  Use one to three tree levels, depending on the
number of significant bits.
2017-02-08 18:50:03 -08:00
Jason Evans
ff4db5014e Remove rtree leading 0 bit optimization.
A subsequent change instead ignores insignificant high bits.
2017-02-08 18:50:03 -08:00
Jason Evans
cdc240d501 Make non-essential inline rtree functions static functions. 2017-02-08 18:50:03 -08:00
Jason Evans
c511a44e99 Split rtree_elm_lookup_hard() out of rtree_elm_lookup().
Anything but a hit in the first element of the lookup cache is
expensive enough to negate the benefits of inlining.
2017-02-08 18:50:03 -08:00
Jason Evans
4a346f5593 Replace rtree path cache with LRU cache.
Rework rtree_ctx_t to encapsulate an rtree leaf LRU lookup cache rather
than a single-path element lookup cache.  The replacement is logically
much simpler, as well as slightly faster in the fast path case and less
prone to degraded performance during non-trivial sequences of lookups.
2017-02-08 18:50:03 -08:00
Jason Evans
0ecf692726 Optimize a branch out of rtree_read() if !dependent. 2017-02-08 18:50:03 -08:00
Jason Evans
d27f29b468 Disentangle arena and extent locking.
Refactor arena and extent locking protocols such that arena and
extent locks are never held when calling into the extent_*_wrapper()
API.  This requires extra care during purging since the arena lock no
longer protects the inner purging logic.  It also requires extra care to
protect extents from being merged with adjacent extents.

Convert extent_t's 'active' flag to an enumerated 'state', so that
retained extents are explicitly marked as such, rather than depending on
ring linkage state.

Refactor the extent collections (and their synchronization) for cached
and retained extents into extents_t.  Incorporate LRU functionality to
support purging.  Incorporate page count accounting, which replaces
arena->ndirty and arena->stats.retained.

Assert that no core locks are held when entering any internal
[de]allocation functions.  This is in addition to existing assertions
that no locks are held when entering external [de]allocation functions.

Audit and document synchronization protocols for all arena_t fields.

This fixes a potential deadlock due to recursive allocation during
gdump, in a similar fashion to b49c649bc1
(Fix lock order reversal during gdump.), but with a necessarily much
broader code impact.
2017-02-01 16:43:46 -08:00
Jason Evans
1b6e43507e Fix/refactor tcaches synchronization.
Synchronize tcaches with tcaches_mtx rather than ctl_mtx.  Add missing
synchronization for tcache flushing.  This bug was introduced by
1cb181ed63 (Implement explicit tcache
support.), which was first released in 4.0.0.
2017-02-01 16:43:46 -08:00
Jason Evans
d0e93ada51 Add witness_assert_depth[_to_rank]().
This makes it possible to make lock state assertions about precisely
which locks are held.
2017-02-01 16:43:46 -08:00
Jason Evans
c0cc5db871 Replace tabs following #define with spaces.
This resolves #564.
2017-01-20 21:45:53 -08:00
Jason Evans
f408643a4c Remove extraneous parens around return arguments.
This resolves #540.
2017-01-20 21:43:07 -08:00
Jason Evans
c4c2592c83 Update brace style.
Add braces around single-line blocks, and remove line breaks before
function-opening braces.

This resolves #537.
2017-01-20 21:43:07 -08:00
Jason Evans
9eb1b1c881 Fix --disable-stats support.
Fix numerous regressions that were exposed by --disable-stats, both in
the core library and in the tests.
2017-01-19 18:31:07 -08:00
Qi Wang
58424e679d Added stats about number of bytes cached in tcache currently. 2017-01-18 10:55:21 -08:00
Mike Hommey
0f7376eb62 Don't rely on OSX SDK malloc/malloc.h for malloc_zone struct definitions
The SDK jemalloc is built against might be not be the latest for various
reasons, but the resulting binary ought to work on newer versions of
OSX.

In order to ensure this, we need the fullest definitions possible, so
copy what we need from the latest version of malloc/malloc.h available
on opensource.apple.com.
2017-01-17 20:13:28 -08:00
Jason Evans
1ff09534b5 Fix prof_realloc() regression.
Mostly revert the prof_realloc() changes in
498856f44a (Move slabs out of chunks.) so
that prof_free_sampled_object() is called when appropriate.  Leave the
prof_tctx_[re]set() optimization in place, but add an assertion to
verify that all eight cases are correctly handled.  Add a comment to
make clear the code ordering, so that the regression originally fixed by
ea8d97b897 (Fix
prof_{malloc,free}_sample_object() call order in prof_realloc().) is not
repeated.

This resolves #499.
2017-01-17 15:16:37 -08:00
Jason Evans
ffbb7dac3d Remove leading blank lines from function bodies.
This resolves #535.
2017-01-13 14:49:24 -08:00