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Disentangle arena and extent locking.

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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.
This commit is contained in:
Jason Evans
2017-01-29 21:57:14 -08:00
parent 1b6e43507e
commit d27f29b468
19 changed files with 772 additions and 650 deletions
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11
include/jemalloc/internal/arena_externs.h
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@@ -13,22 +13,17 @@ extern ssize_t opt_decay_time;
extern const arena_bin_info_t arena_bin_info[NBINS];
extent_t *arena_extent_cache_alloc(tsdn_t *tsdn, arena_t *arena,
extent_hooks_t **r_extent_hooks, void *new_addr, size_t size,
size_t alignment, bool *zero);
void arena_extent_cache_dalloc(tsdn_t *tsdn, arena_t *arena,
extent_hooks_t **r_extent_hooks, extent_t *extent);
void arena_extent_cache_maybe_insert(tsdn_t *tsdn, arena_t *arena,
extent_t *extent, bool cache);
void arena_extent_cache_maybe_remove(tsdn_t *tsdn, arena_t *arena,
extent_t *extent, bool cache);
#ifdef JEMALLOC_JET
size_t arena_slab_regind(extent_t *slab, szind_t binind, const void *ptr);
#endif
extent_t *arena_extent_alloc_large(tsdn_t *tsdn, arena_t *arena,
size_t usize, size_t alignment, bool *zero);
void arena_extent_dalloc_large(tsdn_t *tsdn, arena_t *arena,
void arena_extent_dalloc_large_prep(tsdn_t *tsdn, arena_t *arena,
extent_t *extent, bool locked);
void arena_extent_dalloc_large_finish(tsdn_t *tsdn, arena_t *arena,
extent_t *extent);
void arena_extent_ralloc_large_shrink(tsdn_t *tsdn, arena_t *arena,
extent_t *extent, size_t oldsize);
void arena_extent_ralloc_large_expand(tsdn_t *tsdn, arena_t *arena,