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| author | Jason Evans <jasone@canonware.com> | 2017-01-27 23:03:11 (GMT) |
|---|---|---|
| committer | Jason Evans <jasone@canonware.com> | 2017-02-02 00:43:46 (GMT) |
| commit | ace679ce7435e990df6b789fde4cefeb0e6b992b (patch) | |
| tree | 49aea6b712a74ad9425127a51a6f30559259c318 /src | |
| parent | 5033a9176ac9489805a387c040008b088cf15bda (diff) | |
| download | jemalloc-ace679ce7435e990df6b789fde4cefeb0e6b992b.zip jemalloc-ace679ce7435e990df6b789fde4cefeb0e6b992b.tar.gz jemalloc-ace679ce7435e990df6b789fde4cefeb0e6b992b.tar.bz2 | |
Synchronize extent_grow_next accesses.
This should have been part of 411697adcda2fd75e135cdcdafb95f2bd295dc7f
(Use exponential series to size extents.), which introduced
extent_grow_next.
Diffstat (limited to 'src')
| -rw-r--r-- | src/extent.c | 18 |
1 files changed, 15 insertions, 3 deletions
diff --git a/src/extent.c b/src/extent.c index 0dbde72..e2af2b5 100644 --- a/src/extent.c +++ b/src/extent.c @@ -710,7 +710,7 @@ extent_grow_retained(tsdn_t *tsdn, arena_t *arena, * extent creation as a side effect. */ size = usize + pad; - alloc_size = pind2sz(arena->extent_grow_next); + alloc_size = pind2sz(atomic_read_u(&arena->extent_grow_next)); alloc_size_min = size + PAGE_CEILING(alignment) - PAGE; /* Beware size_t wrap-around. */ if (alloc_size_min < usize) { @@ -809,8 +809,20 @@ extent_grow_retained(tsdn_t *tsdn, arena_t *arena, if (*zero && !extent_zeroed_get(extent)) { memset(extent_addr_get(extent), 0, extent_usize_get(extent)); } - if (arena->extent_grow_next + 1 < NPSIZES) { - arena->extent_grow_next++; + /* + * Increment extent_grow_next, but take care to do so atomically and + * bail out if the increment would exceed the legal range. + */ + while (true) { + pszind_t egn = atomic_read_u(&arena->extent_grow_next); + + if (egn + 1 == NPSIZES) { + break; + } + assert(egn + 1 < NPSIZES); + if (!atomic_cas_u(&arena->extent_grow_next, egn, egn + 1)) { + break; + } } return extent; } |