Commit Graph

8 Commits

Author SHA1 Message Date
Jason Evans
4acd75a694 Add the "stats.allocated" mallctl. 2015-03-23 17:26:53 -07:00
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
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
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
e2deab7a75 Refactor huge allocation to be managed by arenas.
Refactor huge allocation to be managed by arenas (though the global
red-black tree of huge allocations remains for lookup during
deallocation).  This is the logical conclusion of recent changes that 1)
made per arena dss precedence apply to huge allocation, and 2) made it
possible to replace the per arena chunk allocation/deallocation
functions.

Remove the top level huge stats, and replace them with per arena huge
stats.

Normalize function names and types to *dalloc* (some were *dealloc*).

Remove the --enable-mremap option.  As jemalloc currently operates, this
is a performace regression for some applications, but planned work to
logarithmically space huge size classes should provide similar amortized
performance.  The motivation for this change was that mremap-based huge
reallocation forced leaky abstractions that prevented refactoring.
2014-05-15 22:36:41 -07:00
Jason Evans
41b6afb834 Port to FreeBSD.
Use FreeBSD-specific functions (_pthread_mutex_init_calloc_cb(),
_malloc_{pre,post}fork()) to avoid bootstrapping issues due to
allocation in libc and libthr.

Add malloc_strtoumax() and use it instead of strtoul().  Disable
validation code in malloc_vsnprintf() and malloc_strtoumax() until
jemalloc is initialized.  This is necessary because locale
initialization causes allocation for both vsnprintf() and strtoumax().

Force the lazy-lock feature on in order to avoid pthread_self(),
because it causes allocation.

Use syscall(SYS_write, ...) rather than write(...), because libthr wraps
write() and causes allocation.  Without this workaround, it would not be
possible to print error messages in malloc_conf_init() without
substantially reworking bootstrapping.

Fix choose_arena_hard() to look at how many threads are assigned to the
candidate choice, rather than checking whether the arena is
uninitialized.  This bug potentially caused more arenas to be
initialized than necessary.
2012-02-02 23:09:53 -08:00
Jason Evans
4e2e3dd9cf Fix fork-related bugs.
Acquire/release arena bin locks as part of the prefork/postfork.  This
bug made deadlock in the child between fork and exec a possibility.

Split jemalloc_postfork() into jemalloc_postfork_{parent,child}() so
that the child can reinitialize mutexes rather than unlocking them.  In
practice, this bug tended not to cause problems.
2012-03-13 16:31:41 -07:00
Jason Evans
7427525c28 Move repo contents in jemalloc/ to top level. 2011-03-31 20:36:17 -07:00