Commit Graph

12 Commits

Author SHA1 Message Date
Qinfan Wu
ff6a31d3b9 Refactor chunk map.
Break the chunk map into two separate arrays, in order to improve cache
locality. This is related to issue #23.
2014-09-04 22:22:52 -07:00
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
aravind
fb7fe50a88 Add support for user-specified chunk allocators/deallocators.
Add new mallctl endpoints "arena<i>.chunk.alloc" and
"arena<i>.chunk.dealloc" to allow userspace to configure
jemalloc's chunk allocator and deallocator on a per-arena
basis.
2014-05-12 10:46:03 -07:00
Jason Evans
609ae595f0 Add arena-specific and selective dss allocation.
Add the "arenas.extend" mallctl, so that it is possible to create new
arenas that are outside the set that jemalloc automatically multiplexes
threads onto.

Add the ALLOCM_ARENA() flag for {,r,d}allocm(), so that it is possible
to explicitly allocate from a particular arena.

Add the "opt.dss" mallctl, which controls the default precedence of dss
allocation relative to mmap allocation.

Add the "arena.<i>.dss" mallctl, which makes it possible to set the
default dss precedence on a per arena or global basis.

Add the "arena.<i>.purge" mallctl, which obsoletes "arenas.purge".

Add the "stats.arenas.<i>.dss" mallctl.
2012-10-12 18:26:16 -07:00
Jason Evans
20f1fc95ad Fix fork(2)-related deadlocks.
Add a library constructor for jemalloc that initializes the allocator.
This fixes a race that could occur if threads were created by the main
thread prior to any memory allocation, followed by fork(2), and then
memory allocation in the child process.

Fix the prefork/postfork functions to acquire/release the ctl, prof, and
rtree mutexes.  This fixes various fork() child process deadlocks, but
one possible deadlock remains (intentionally) unaddressed: prof
backtracing can acquire runtime library mutexes, so deadlock is still
possible if heap profiling is enabled during fork().  This deadlock is
known to be a real issue in at least the case of libgcc-based
backtracing.

Reported by tfengjun.
2012-10-09 15:21:46 -07:00
Jason Evans
a8f8d7540d Remove mmap_unaligned.
Remove mmap_unaligned, which was used to heuristically decide whether to
optimistically call mmap() in such a way that could reduce the total
number of system calls.  If I remember correctly, the intention of
mmap_unaligned was to avoid always executing the slow path in the
presence of ASLR.  However, that reasoning seems to have been based on a
flawed understanding of how ASLR actually works.  Although ASLR
apparently causes mmap() to ignore address requests, it does not cause
total placement randomness, so there is a reasonable expectation that
iterative mmap() calls will start returning chunk-aligned mappings once
the first chunk has been properly aligned.
2012-04-21 19:17:21 -07:00
Mike Hommey
eae269036c Add alignment support to chunk_alloc(). 2012-04-10 14:51:39 -07:00
Jason Evans
cd9a1346e9 Implement tsd.
Implement tsd, which is a TLS/TSD abstraction that uses one or both
internally.  Modify bootstrapping such that no tsd's are utilized until
allocation is safe.

Remove malloc_[v]tprintf(), and use malloc_snprintf() instead.

Fix %p argument size handling in malloc_vsnprintf().

Fix a long-standing statistics-related bug in the "thread.arena"
mallctl that could cause crashes due to linked list corruption.
2012-03-23 15:14:55 -07:00
Jason Evans
4162627757 Remove the swap feature.
Remove the swap feature, which enabled per application swap files.  In
practice this feature has not proven itself useful to users.
2012-02-13 10:56:17 -08:00
Jason Evans
7372b15a31 Reduce cpp conditional logic complexity.
Convert configuration-related cpp conditional logic to use static
constant variables, e.g.:

  #ifdef JEMALLOC_DEBUG
    [...]
  #endif

becomes:

  if (config_debug) {
    [...]
  }

The advantage is clearer, more concise code.  The main disadvantage is
that data structures no longer have conditionally defined fields, so
they pay the cost of all fields regardless of whether they are used.  In
practice, this is only a minor concern; config_stats will go away in an
upcoming change, and config_prof is the only other major feature that
depends on more than a few special-purpose fields.
2012-02-10 20:22:09 -08:00
Jason Evans
12a4887826 Fix huge_ralloc to maintain chunk statistics.
Fix huge_ralloc() to properly maintain chunk statistics when using
mremap(2).
2011-11-11 14:41:59 -08:00
Jason Evans
7427525c28 Move repo contents in jemalloc/ to top level. 2011-03-31 20:36:17 -07:00