Commit Graph

21 Commits

Author SHA1 Message Date
Jason Evans
881fbf762f Prefer old/low extent_t structures during reuse.
Rather than using a LIFO queue to track available extent_t structures,
use a red-black tree, and always choose the oldest/lowest available
during reuse.
2017-04-17 14:47:45 -07:00
Qi Wang
ccfe68a916 Pass alloc_ctx down profiling path.
With this change, when profiling is enabled, we avoid doing redundant rtree
lookups. Also changed dalloc_atx_t to alloc_atx_t, as it's now used on
allocation path as well (to speed up profiling).
2017-04-12 13:55:39 -07:00
David Goldblatt
e709fae1d7 Header refactoring: move atomic.h out of the catch-all 2017-04-11 11:52:30 -07:00
David Goldblatt
0237870c60 Header refactoring: break out ql.h dependencies 2017-04-11 11:52:30 -07:00
Qi Wang
bfa530b75b Pass dealloc_ctx down free() fast path.
This gets rid of the redundent rtree lookup down fast path.
2017-04-11 09:58:12 -07:00
David Goldblatt
56b72c7b17 Transition arena struct fields to C11 atomics 2017-04-05 16:25:37 -07:00
David Goldblatt
7da04a6b09 Convert prng module to use C11-style atomics 2017-04-04 16:45:52 -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
Jason Evans
3a2b183d5f Convert arena_t's purging field to non-atomic bool.
The decay mutex already protects all accesses.
2017-03-10 10:14:30 -08:00
Qi Wang
ec532e2c5c Implement per-CPU arena.
The new feature, opt.percpu_arena, determines thread-arena association
dynamically based CPU id. Three modes are supported: "percpu", "phycpu"
and disabled.

"percpu" uses the current core id (with help from sched_getcpu())
directly as the arena index, while "phycpu" will assign threads on the
same physical CPU to the same arena. In other words, "percpu" means # of
arenas == # of CPUs, while "phycpu" has # of arenas == 1/2 * (# of
CPUs). Note that no runtime check on whether hyper threading is enabled
is added yet.

When enabled, threads will be migrated between arenas when a CPU change
is detected. In the current design, to reduce overhead from reading CPU
id, each arena tracks the thread accessed most recently. When a new
thread comes in, we will read CPU id and update arena if necessary.
2017-03-08 23:19:01 -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
Jason Evans
d61a5f76b2 Convert arena_decay_t's time to be atomically synchronized. 2017-03-02 19:43:06 -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
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
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
David Goldblatt
77cccac8cd Break up headers into constituent parts
This is part of a broader change to make header files better represent the
dependencies between one another (see
https://github.com/jemalloc/jemalloc/issues/533). It breaks up component headers
into smaller parts that can be made to have a simpler dependency graph.

For the autogenerated headers (smoothstep.h and size_classes.h), no splitting
was necessary, so I didn't add support to emit multiple headers.
2017-01-12 15:43:51 -08:00