Commit Graph

276 Commits

Author SHA1 Message Date
Jason Evans
2195ba4e1f Normalize *_link and link_* fields to all be *_link. 2015-02-15 16:43:52 -08:00
Jason Evans
41cfe03f39 If MALLOCX_ARENA(a) is specified, use it during tcache fill. 2015-02-13 15:28:56 -08:00
Jason Evans
5f7140b045 Make prof_tctx accesses atomic.
Although exceedingly unlikely, it appears that writes to the prof_tctx
field of arena_chunk_map_misc_t could be reordered such that a stale
value could be read during deallocation, with profiler metadata
corruption and invalid pointer dereferences being the most likely
effects.
2015-02-12 15:54:53 -08:00
Jason Evans
88fef7ceda Refactor huge_*() calls into arena internals.
Make redirects to the huge_*() API the arena code's responsibility,
since arenas now take responsibility for all allocation sizes.
2015-02-12 14:06:37 -08:00
Jason Evans
cbf3a6d703 Move centralized chunk management into arenas.
Migrate all centralized data structures related to huge allocations and
recyclable chunks into arena_t, so that each arena can manage huge
allocations and recyclable virtual memory completely independently of
other arenas.

Add chunk node caching to arenas, in order to avoid contention on the
base allocator.

Use chunks_rtree to look up huge allocations rather than a red-black
tree.  Maintain a per arena unsorted list of huge allocations (which
will be needed to enumerate huge allocations during arena reset).

Remove the --enable-ivsalloc option, make ivsalloc() always available,
and use it for size queries if --enable-debug is enabled.  The only
practical implications to this removal are that 1) ivsalloc() is now
always available during live debugging (and the underlying radix tree is
available during core-based debugging), and 2) size query validation can
no longer be enabled independent of --enable-debug.

Remove the stats.chunks.{current,total,high} mallctls, and replace their
underlying statistics with simpler atomically updated counters used
exclusively for gdump triggering.  These statistics are no longer very
useful because each arena manages chunks independently, and per arena
statistics provide similar information.

Simplify chunk synchronization code, now that base chunk allocation
cannot cause recursive lock acquisition.
2015-02-12 00:15:56 -08:00
Jason Evans
051eae8cc5 Remove unnecessary xchg* lock prefixes. 2015-02-10 16:05:52 -08:00
Jason Evans
1cb181ed63 Implement explicit tcache support.
Add the MALLOCX_TCACHE() and MALLOCX_TCACHE_NONE macros, which can be
used in conjunction with the *allocx() API.

Add the tcache.create, tcache.flush, and tcache.destroy mallctls.

This resolves #145.
2015-02-09 17:44:48 -08:00
Jason Evans
23694b0745 Fix arena_get() for (!init_if_missing && refresh_if_missing) case.
Fix arena_get() to refresh the cache as needed in the (!init_if_missing
&& refresh_if_missing) case.

This flaw was introduced by the initial arena_get() implementation,
which was part of 8bb3198f72 (Refactor/fix
arenas manipulation.).
2015-02-09 17:43:10 -08:00
Jason Evans
8d0e04d42f Refactor rtree to be lock-free.
Recent huge allocation refactoring associates huge allocations with
arenas, but it remains necessary to quickly look up huge allocation
metadata during reallocation/deallocation.  A global radix tree remains
a good solution to this problem, but locking would have become the
primary bottleneck after (upcoming) migration of chunk management from
global to per arena data structures.

This lock-free implementation uses double-checked reads to traverse the
tree, so that in the steady state, each read or write requires only a
single atomic operation.

This implementation also assures that no more than two tree levels
actually exist, through a combination of careful virtual memory
allocation which makes large sparse nodes cheap, and skipping the root
node on x64 (possible because the top 16 bits are all 0 in practice).
2015-02-04 16:51:53 -08:00
Jason Evans
c810fcea1f Add (x != 0) assertion to lg_floor(x).
lg_floor(0) is undefined, but depending on compiler options may not
cause a crash.  This assertion makes it harder to accidentally abuse
lg_floor().
2015-02-04 16:51:53 -08:00
Jason Evans
f500a10b2e Refactor base_alloc() to guarantee demand-zeroed memory.
Refactor base_alloc() to guarantee that allocations are carved from
demand-zeroed virtual memory.  This supports sparse data structures such
as multi-page radix tree nodes.

Enhance base_alloc() to keep track of fragments which were too small to
support previous allocation requests, and try to consume them during
subsequent requests.  This becomes important when request sizes commonly
approach or exceed the chunk size (as could radix tree node
allocations).
2015-02-04 16:51:53 -08:00
Jason Evans
918a1a5b3f Reduce extent_node_t size to fit in one cache line. 2015-02-04 16:51:53 -08:00
Jason Evans
a55dfa4b0a Implement more atomic operations.
- atomic_*_p().
- atomic_cas_*().
- atomic_write_*().
2015-02-04 16:50:05 -08:00
Jason Evans
f8723572d8 Add missing prototypes for bootstrap_{malloc,calloc,free}(). 2015-02-04 16:50:04 -08:00
Jason Evans
5b8ed5b7c9 Implement the prof.gdump mallctl.
This feature makes it possible to toggle the gdump feature on/off during
program execution, whereas the the opt.prof_dump mallctl value can only
be set during program startup.

This resolves #72.
2015-01-25 21:21:35 -08:00
Jason Evans
4581b97809 Implement metadata statistics.
There are three categories of metadata:

- Base allocations are used for bootstrap-sensitive internal allocator
  data structures.
- Arena chunk headers comprise pages which track the states of the
  non-metadata pages.
- Internal allocations differ from application-originated allocations
  in that they are for internal use, and that they are omitted from heap
  profiles.

The metadata statistics comprise the metadata categories as follows:

- stats.metadata: All metadata -- base + arena chunk headers + internal
  allocations.
- stats.arenas.<i>.metadata.mapped: Arena chunk headers.
- stats.arenas.<i>.metadata.allocated: Internal allocations.  This is
  reported separately from the other metadata statistics because it
  overlaps with the allocated and active statistics, whereas the other
  metadata statistics do not.

Base allocations are not reported separately, though their magnitude can
be computed by subtracting the arena-specific metadata.

This resolves #163.
2015-01-23 23:34:43 -08:00
Jason Evans
10aff3f3e1 Refactor bootstrapping to delay tsd initialization.
Refactor bootstrapping to delay tsd initialization, primarily to support
integration with FreeBSD's libc.

Refactor a0*() for internal-only use, and add the
bootstrap_{malloc,calloc,free}() API for use by FreeBSD's libc.  This
separation limits use of the a0*() functions to metadata allocation,
which doesn't require malloc/calloc/free API compatibility.

This resolves #170.
2015-01-22 14:04:27 -08:00
Abhishek Kulkarni
b617df81bb Add missing symbols to private_symbols.txt.
This resolves #185.
2015-01-21 12:44:35 -08:00
Guilherme Goncalves
51f86346c0 Add a isblank definition for MSVC < 2013 2015-01-09 14:33:46 -08:00
Guilherme Goncalves
2c5cb613df Introduce two new modes of junk filling: "alloc" and "free".
In addition to true/false, opt.junk can now be either "alloc" or "free",
giving applications the possibility of junking memory only on allocation
or deallocation.

This resolves #172.
2014-12-14 17:07:26 -08:00
Daniel Micay
b74041fb6e Ignore MALLOC_CONF in set{uid,gid,cap} binaries.
This eliminates the malloc tunables as tools for an attacker.

Closes #173
2014-12-14 15:36:15 -08:00
Jason Evans
e12eaf93dc Style and spelling fixes. 2014-12-08 16:34:04 -08:00
Chih-hung Hsieh
59cd80e6c6 Add a C11 atomics-based implementation of atomic.h API. 2014-12-06 21:17:49 -08:00
Jason Evans
a18c2b1f15 Style fixes. 2014-12-05 17:49:47 -08:00
Daniel Micay
879e76a9e5 teach the dss chunk allocator to handle new_addr
This provides in-place expansion of huge allocations when the end of the
allocation is at the end of the sbrk heap. There's already the ability
to extend in-place via recycled chunks but this handles the initial
growth of the heap via repeated vector / string reallocations.

A possible future extension could allow realloc to go from the following:

    | huge allocation | recycled chunks |
                                        ^ dss_end

To a larger allocation built from recycled *and* new chunks:

    |                      huge allocation                      |
                                                                ^ dss_end

Doing that would involve teaching the chunk recycling code to request
new chunks to satisfy the request. The chunk_dss code wouldn't require
any further changes.

    #include <stdlib.h>

    int main(void) {
        size_t chunk = 4 * 1024 * 1024;
        void *ptr = NULL;
        for (size_t size = chunk; size < chunk * 128; size *= 2) {
            ptr = realloc(ptr, size);
            if (!ptr) return 1;
        }
    }

dss:secondary: 0.083s
dss:primary: 0.083s

After:

dss:secondary: 0.083s
dss:primary: 0.003s

The dss heap grows in the upwards direction, so the oldest chunks are at
the low addresses and they are used first. Linux prefers to grow the
mmap heap downwards, so the trick will not work in the *current* mmap
chunk allocator as a huge allocation will only be at the top of the heap
in a contrived case.
2014-11-28 16:11:19 -08:00
Guilherme Goncalves
a2136025c4 Remove extra definition of je_tsd_boot on win32. 2014-11-18 19:08:18 -02:00
Jason Evans
9cf2be0a81 Make quarantine_init() static. 2014-11-07 14:50:38 -08:00
Jason Evans
c002a5c800 Fix two quarantine regressions.
Fix quarantine to actually update tsd when expanding, and to avoid
double initialization (leaking the first quarantine) due to recursive
initialization.

This resolves #161.
2014-11-04 18:03:11 -08:00
Jason Evans
d7a9bab92d Fix arena_sdalloc() to use promoted size (second attempt).
Unlike the preceeding attempted fix, this version avoids the potential
for converting an invalid bin index to a size class.
2014-10-31 22:26:24 -07:00
Jason Evans
6da2e9d4f6 Fix arena_sdalloc() to use promoted size. 2014-10-31 17:08:13 -07:00
Jason Evans
cfc5706f69 Miscellaneous cleanups. 2014-10-30 23:18:45 -07:00
Daniel Micay
d33f834591 avoid redundant chunk header reads
* use sized deallocation in iralloct_realign
* iralloc and ixalloc always need the old size, so pass it in from the
  caller where it's often already calculated
2014-10-30 17:06:38 -07:00
Daniel Micay
809b0ac391 mark huge allocations as unlikely
This cleans up the fast path a bit more by moving away more code.
2014-10-30 17:06:38 -07:00
Jason Evans
9b41ac909f Fix huge allocation statistics. 2014-10-14 22:20:00 -07:00
Jason Evans
3c4d92e82a Add per size class huge allocation statistics.
Add per size class huge allocation statistics, and normalize various
stats:
- Change the arenas.nlruns type from size_t to unsigned.
- Add the arenas.nhchunks and arenas.hchunks.<i>.size mallctl's.
- Replace the stats.arenas.<i>.bins.<j>.allocated mallctl with
  stats.arenas.<i>.bins.<j>.curregs .
- Add the 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 mallctl's.
2014-10-12 23:02:10 -07:00
Jason Evans
44c97b712e Fix a prof_tctx_t/prof_tdata_t cleanup race.
Fix a prof_tctx_t/prof_tdata_t cleanup race by storing a copy of thr_uid
in prof_tctx_t, so that the associated tdata need not be present during
tctx teardown.
2014-10-12 13:03:20 -07:00
Jason Evans
381c23dd9d Remove arena_dalloc_bin_run() clean page preservation.
Remove code in arena_dalloc_bin_run() that preserved the "clean" state
of trailing clean pages by splitting them into a separate run during
deallocation.  This was a useful mechanism for reducing dirty page
churn when bin runs comprised many pages, but bin runs are now quite
small.

Remove the nextind field from arena_run_t now that it is no longer
needed, and change arena_run_t's bin field (arena_bin_t *) to binind
(index_t).  These two changes remove 8 bytes of chunk header overhead
per page, which saves 1/512 of all arena chunk memory.
2014-10-10 23:01:03 -07:00
Jason Evans
81e547566e Add --with-lg-tiny-min, generalize --with-lg-quantum. 2014-10-10 22:35:07 -07:00
Jason Evans
fc0b3b7383 Add configure options.
Add:
  --with-lg-page
  --with-lg-page-sizes
  --with-lg-size-class-group
  --with-lg-quantum

Get rid of STATIC_PAGE_SHIFT, in favor of directly setting LG_PAGE.

Fix various edge conditions exposed by the configure options.
2014-10-09 22:44:37 -07:00
Daniel Micay
f22214a29d Use regular arena allocation for huge tree nodes.
This avoids grabbing the base mutex, as a step towards fine-grained
locking for huge allocations. The thread cache also provides a tiny
(~3%) improvement for serial huge allocations.
2014-10-07 23:57:09 -07:00
Jason Evans
8bb3198f72 Refactor/fix arenas manipulation.
Abstract arenas access to use arena_get() (or a0get() where appropriate)
rather than directly reading e.g. arenas[ind].  Prior to the addition of
the arenas.extend mallctl, the worst possible outcome of directly
accessing arenas was a stale read, but arenas.extend may allocate and
assign a new array to arenas.

Add a tsd-based arenas_cache, which amortizes arenas reads.  This
introduces some subtle bootstrapping issues, with tsd_boot() now being
split into tsd_boot[01]() to support tsd wrapper allocation
bootstrapping, as well as an arenas_cache_bypass tsd variable which
dynamically terminates allocation of arenas_cache itself.

Promote a0malloc(), a0calloc(), and a0free() to be generally useful for
internal allocation, and use them in several places (more may be
appropriate).

Abstract arena->nthreads management and fix a missing decrement during
thread destruction (recent tsd refactoring left arenas_cleanup()
unused).

Change arena_choose() to propagate OOM, and handle OOM in all callers.
This is important for providing consistent allocation behavior when the
MALLOCX_ARENA() flag is being used.  Prior to this fix, it was possible
for an OOM to result in allocation silently allocating from a different
arena than the one specified.
2014-10-07 23:14:57 -07:00
Jason Evans
155bfa7da1 Normalize size classes.
Normalize size classes to use the same number of size classes per size
doubling (currently hard coded to 4), across the intire range of size
classes.  Small size classes already used this spacing, but in order to
support this change, additional small size classes now fill [4 KiB .. 16
KiB).  Large size classes range from [16 KiB .. 4 MiB).  Huge size
classes now support non-multiples of the chunk size in order to fill (4
MiB .. 16 MiB).
2014-10-06 01:45:13 -07:00
Daniel Micay
a95018ee81 Attempt to expand huge allocations in-place.
This adds support for expanding huge allocations in-place by requesting
memory at a specific address from the chunk allocator.

It's currently only implemented for the chunk recycling path, although
in theory it could also be done by optimistically allocating new chunks.
On Linux, it could attempt an in-place mremap. However, that won't work
in practice since the heap is grown downwards and memory is not unmapped
(in a normal build, at least).

Repeated vector reallocation micro-benchmark:

    #include <string.h>
    #include <stdlib.h>

    int main(void) {
        for (size_t i = 0; i < 100; i++) {
            void *ptr = NULL;
            size_t old_size = 0;
            for (size_t size = 4; size < (1 << 30); size *= 2) {
                ptr = realloc(ptr, size);
                if (!ptr) return 1;
                memset(ptr + old_size, 0xff, size - old_size);
                old_size = size;
            }
            free(ptr);
        }
    }

The glibc allocator fails to do any in-place reallocations on this
benchmark once it passes the M_MMAP_THRESHOLD (default 128k) but it
elides the cost of copies via mremap, which is currently not something
that jemalloc can use.

With this improvement, jemalloc still fails to do any in-place huge
reallocations for the first outer loop, but then succeeds 100% of the
time for the remaining 99 iterations. The time spent doing allocations
and copies drops down to under 5%, with nearly all of it spent doing
purging + faulting (when huge pages are disabled) and the array memset.

An improved mremap API (MREMAP_RETAIN - #138) would be far more general
but this is a portable optimization and would still be useful on Linux
for xallocx.

Numbers with transparent huge pages enabled:

glibc (copies elided via MREMAP_MAYMOVE): 8.471s

jemalloc: 17.816s
jemalloc + no-op madvise: 13.236s

jemalloc + this commit: 6.787s
jemalloc + this commit + no-op madvise: 6.144s

Numbers with transparent huge pages disabled:

glibc (copies elided via MREMAP_MAYMOVE): 15.403s

jemalloc: 39.456s
jemalloc + no-op madvise: 12.768s

jemalloc + this commit: 15.534s
jemalloc + this commit + no-op madvise: 6.354s

Closes #137
2014-10-05 14:47:01 -07:00
Jason Evans
e9a3fa2e09 Add missing header includes in jemalloc/jemalloc.h .
Add stdlib.h, stdbool.h, and stdint.h to jemalloc/jemalloc.h so that
applications only have to #include <jemalloc/jemalloc.h>.

This resolves #132.
2014-10-05 12:05:37 -07:00
Jason Evans
16854ebeb7 Don't disable tcache for lazy-lock.
Don't disable tcache when lazy-lock is configured.  There already exists
a mechanism to disable tcache, but doing so automatically due to
lazy-lock causes surprising performance behavior.
2014-10-04 15:00:51 -07:00
Jason Evans
34e85b4182 Make prof-related inline functions always-inline. 2014-10-04 11:26:05 -07:00
Jason Evans
029d44cf8b Fix tsd cleanup regressions.
Fix tsd cleanup regressions that were introduced in
5460aa6f66 (Convert all tsd variables to
reside in a single tsd structure.).  These regressions were twofold:

1) tsd_tryget() should never (and need never) return NULL.  Rename it to
   tsd_fetch() and simplify all callers.
2) tsd_*_set() must only be called when tsd is in the nominal state,
   because cleanup happens during the nominal-->purgatory transition,
   and re-initialization must not happen while in the purgatory state.
   Add tsd_nominal() and use it as needed.  Note that tsd_*{p,}_get()
   can still be used as long as no re-initialization that would require
   cleanup occurs.  This means that e.g. the thread_allocated counter
   can be updated unconditionally.
2014-10-04 11:22:55 -07:00
Jason Evans
fc12c0b8bc Implement/test/fix prof-related mallctl's.
Implement/test/fix the opt.prof_thread_active_init,
prof.thread_active_init, and thread.prof.active mallctl's.

Test/fix the thread.prof.name mallctl.

Refactor opt_prof_active to be read-only and move mutable state into the
prof_active variable.  Stop leaning on ctl-related locking for
protection.
2014-10-03 23:25:30 -07:00
Jason Evans
551ebc4364 Convert to uniform style: cond == false --> !cond 2014-10-03 10:16:09 -07:00
Jason Evans
20c31deaae Test prof.reset mallctl and fix numerous discovered bugs. 2014-10-02 23:01:10 -07:00