server-skynet-source-3rd-je.../src/large.c
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

347 lines
9.9 KiB
C

#define JEMALLOC_LARGE_C_
#include "jemalloc/internal/jemalloc_internal.h"
/******************************************************************************/
void *
large_malloc(tsdn_t *tsdn, arena_t *arena, size_t usize, bool zero) {
assert(usize == s2u(usize));
return large_palloc(tsdn, arena, usize, CACHELINE, zero);
}
void *
large_palloc(tsdn_t *tsdn, arena_t *arena, size_t usize, size_t alignment,
bool zero) {
size_t ausize;
extent_t *extent;
bool is_zeroed;
UNUSED bool idump JEMALLOC_CC_SILENCE_INIT(false);
assert(!tsdn_null(tsdn) || arena != NULL);
ausize = sa2u(usize, alignment);
if (unlikely(ausize == 0 || ausize > LARGE_MAXCLASS)) {
return NULL;
}
/*
* Copy zero into is_zeroed and pass the copy to extent_alloc(), so that
* it is possible to make correct junk/zero fill decisions below.
*/
is_zeroed = zero;
if (likely(!tsdn_null(tsdn))) {
arena = arena_choose(tsdn_tsd(tsdn), arena);
}
if (unlikely(arena == NULL) || (extent = arena_extent_alloc_large(tsdn,
arena, usize, alignment, &is_zeroed)) == NULL) {
return NULL;
}
/* Insert extent into large. */
malloc_mutex_lock(tsdn, &arena->large_mtx);
extent_list_append(&arena->large, extent);
malloc_mutex_unlock(tsdn, &arena->large_mtx);
if (config_prof && arena_prof_accum(tsdn, arena, usize)) {
prof_idump(tsdn);
}
if (zero || (config_fill && unlikely(opt_zero))) {
if (!is_zeroed) {
memset(extent_addr_get(extent), 0,
extent_usize_get(extent));
}
} else if (config_fill && unlikely(opt_junk_alloc)) {
memset(extent_addr_get(extent), JEMALLOC_ALLOC_JUNK,
extent_usize_get(extent));
}
arena_decay_tick(tsdn, arena);
return extent_addr_get(extent);
}
#ifdef JEMALLOC_JET
#undef large_dalloc_junk
#define large_dalloc_junk JEMALLOC_N(n_large_dalloc_junk)
#endif
void
large_dalloc_junk(void *ptr, size_t usize) {
memset(ptr, JEMALLOC_FREE_JUNK, usize);
}
#ifdef JEMALLOC_JET
#undef large_dalloc_junk
#define large_dalloc_junk JEMALLOC_N(large_dalloc_junk)
large_dalloc_junk_t *large_dalloc_junk = JEMALLOC_N(n_large_dalloc_junk);
#endif
#ifdef JEMALLOC_JET
#undef large_dalloc_maybe_junk
#define large_dalloc_maybe_junk JEMALLOC_N(n_large_dalloc_maybe_junk)
#endif
void
large_dalloc_maybe_junk(void *ptr, size_t usize) {
if (config_fill && have_dss && unlikely(opt_junk_free)) {
/*
* Only bother junk filling if the extent isn't about to be
* unmapped.
*/
if (!config_munmap || (have_dss && extent_in_dss(ptr))) {
large_dalloc_junk(ptr, usize);
}
}
}
#ifdef JEMALLOC_JET
#undef large_dalloc_maybe_junk
#define large_dalloc_maybe_junk JEMALLOC_N(large_dalloc_maybe_junk)
large_dalloc_maybe_junk_t *large_dalloc_maybe_junk =
JEMALLOC_N(n_large_dalloc_maybe_junk);
#endif
static bool
large_ralloc_no_move_shrink(tsdn_t *tsdn, extent_t *extent, size_t usize) {
arena_t *arena = extent_arena_get(extent);
size_t oldusize = extent_usize_get(extent);
extent_hooks_t *extent_hooks = extent_hooks_get(arena);
size_t diff = extent_size_get(extent) - (usize + large_pad);
assert(oldusize > usize);
if (extent_hooks->split == NULL) {
return true;
}
/* Split excess pages. */
if (diff != 0) {
extent_t *trail = extent_split_wrapper(tsdn, arena,
&extent_hooks, extent, usize + large_pad, usize, diff,
diff);
if (trail == NULL) {
return true;
}
if (config_fill && unlikely(opt_junk_free)) {
large_dalloc_maybe_junk(extent_addr_get(trail),
extent_usize_get(trail));
}
arena_extent_cache_dalloc(tsdn, arena, &extent_hooks, trail);
}
arena_extent_ralloc_large_shrink(tsdn, arena, extent, oldusize);
return false;
}
static bool
large_ralloc_no_move_expand(tsdn_t *tsdn, extent_t *extent, size_t usize,
bool zero) {
arena_t *arena = extent_arena_get(extent);
size_t oldusize = extent_usize_get(extent);
extent_hooks_t *extent_hooks = extent_hooks_get(arena);
size_t trailsize = usize - extent_usize_get(extent);
if (extent_hooks->merge == NULL) {
return true;
}
bool is_zeroed_trail = false;
bool commit = true;
extent_t *trail;
if ((trail = extent_alloc_cache(tsdn, arena, &extent_hooks,
extent_past_get(extent), trailsize, 0, CACHELINE, &is_zeroed_trail,
&commit, false)) == NULL) {
if ((trail = extent_alloc_wrapper(tsdn, arena, &extent_hooks,
extent_past_get(extent), trailsize, 0, CACHELINE,
&is_zeroed_trail, &commit, false)) == NULL) {
return true;
}
}
if (extent_merge_wrapper(tsdn, arena, &extent_hooks, extent, trail)) {
extent_dalloc_wrapper(tsdn, arena, &extent_hooks, trail);
return true;
}
if (zero || (config_fill && unlikely(opt_zero))) {
if (config_cache_oblivious) {
/*
* Zero the trailing bytes of the original allocation's
* last page, since they are in an indeterminate state.
* There will always be trailing bytes, because ptr's
* offset from the beginning of the extent is a multiple
* of CACHELINE in [0 .. PAGE).
*/
void *zbase = (void *)
((uintptr_t)extent_addr_get(extent) + oldusize);
void *zpast = PAGE_ADDR2BASE((void *)((uintptr_t)zbase +
PAGE));
size_t nzero = (uintptr_t)zpast - (uintptr_t)zbase;
assert(nzero > 0);
memset(zbase, 0, nzero);
}
if (!is_zeroed_trail) {
memset((void *)((uintptr_t)extent_addr_get(extent) +
oldusize), 0, usize - oldusize);
}
} else if (config_fill && unlikely(opt_junk_alloc)) {
memset((void *)((uintptr_t)extent_addr_get(extent) + oldusize),
JEMALLOC_ALLOC_JUNK, usize - oldusize);
}
arena_extent_ralloc_large_expand(tsdn, arena, extent, oldusize);
return false;
}
bool
large_ralloc_no_move(tsdn_t *tsdn, extent_t *extent, size_t usize_min,
size_t usize_max, bool zero) {
assert(s2u(extent_usize_get(extent)) == extent_usize_get(extent));
/* The following should have been caught by callers. */
assert(usize_min > 0 && usize_max <= LARGE_MAXCLASS);
/* Both allocation sizes must be large to avoid a move. */
assert(extent_usize_get(extent) >= LARGE_MINCLASS && usize_max >=
LARGE_MINCLASS);
if (usize_max > extent_usize_get(extent)) {
/* Attempt to expand the allocation in-place. */
if (!large_ralloc_no_move_expand(tsdn, extent, usize_max,
zero)) {
arena_decay_tick(tsdn, extent_arena_get(extent));
return false;
}
/* Try again, this time with usize_min. */
if (usize_min < usize_max && usize_min >
extent_usize_get(extent) &&
large_ralloc_no_move_expand(tsdn, extent, usize_min,
zero)) {
arena_decay_tick(tsdn, extent_arena_get(extent));
return false;
}
}
/*
* Avoid moving the allocation if the existing extent size accommodates
* the new size.
*/
if (extent_usize_get(extent) >= usize_min && extent_usize_get(extent) <=
usize_max) {
arena_decay_tick(tsdn, extent_arena_get(extent));
return false;
}
/* Attempt to shrink the allocation in-place. */
if (extent_usize_get(extent) > usize_max) {
if (!large_ralloc_no_move_shrink(tsdn, extent, usize_max)) {
arena_decay_tick(tsdn, extent_arena_get(extent));
return false;
}
}
return true;
}
static void *
large_ralloc_move_helper(tsdn_t *tsdn, arena_t *arena, size_t usize,
size_t alignment, bool zero) {
if (alignment <= CACHELINE) {
return large_malloc(tsdn, arena, usize, zero);
}
return large_palloc(tsdn, arena, usize, alignment, zero);
}
void *
large_ralloc(tsdn_t *tsdn, arena_t *arena, extent_t *extent, size_t usize,
size_t alignment, bool zero, tcache_t *tcache) {
void *ret;
size_t copysize;
/* The following should have been caught by callers. */
assert(usize > 0 && usize <= LARGE_MAXCLASS);
/* Both allocation sizes must be large to avoid a move. */
assert(extent_usize_get(extent) >= LARGE_MINCLASS && usize >=
LARGE_MINCLASS);
/* Try to avoid moving the allocation. */
if (!large_ralloc_no_move(tsdn, extent, usize, usize, zero)) {
return extent_addr_get(extent);
}
/*
* usize and old size are different enough that we need to use a
* different size class. In that case, fall back to allocating new
* space and copying.
*/
ret = large_ralloc_move_helper(tsdn, arena, usize, alignment, zero);
if (ret == NULL) {
return NULL;
}
copysize = (usize < extent_usize_get(extent)) ? usize :
extent_usize_get(extent);
memcpy(ret, extent_addr_get(extent), copysize);
isdalloct(tsdn, extent, extent_addr_get(extent),
extent_usize_get(extent), tcache, true);
return ret;
}
/*
* junked_locked indicates whether the extent's data have been junk-filled, and
* whether the arena's lock is currently held. The arena's large_mtx is
* independent of these considerations.
*/
static void
large_dalloc_prep_impl(tsdn_t *tsdn, arena_t *arena, extent_t *extent,
bool junked_locked) {
malloc_mutex_lock(tsdn, &arena->large_mtx);
extent_list_remove(&arena->large, extent);
malloc_mutex_unlock(tsdn, &arena->large_mtx);
if (!junked_locked) {
large_dalloc_maybe_junk(extent_addr_get(extent),
extent_usize_get(extent));
}
arena_extent_dalloc_large_prep(tsdn, arena, extent, junked_locked);
}
static void
large_dalloc_finish_impl(tsdn_t *tsdn, arena_t *arena, extent_t *extent) {
arena_extent_dalloc_large_finish(tsdn, arena, extent);
}
void
large_dalloc_prep_junked_locked(tsdn_t *tsdn, extent_t *extent) {
large_dalloc_prep_impl(tsdn, extent_arena_get(extent), extent, true);
}
void
large_dalloc_finish(tsdn_t *tsdn, extent_t *extent) {
large_dalloc_finish_impl(tsdn, extent_arena_get(extent), extent);
}
void
large_dalloc(tsdn_t *tsdn, extent_t *extent) {
arena_t *arena = extent_arena_get(extent);
large_dalloc_prep_impl(tsdn, arena, extent, false);
large_dalloc_finish_impl(tsdn, arena, extent);
arena_decay_tick(tsdn, arena);
}
size_t
large_salloc(tsdn_t *tsdn, const extent_t *extent) {
return extent_usize_get(extent);
}
prof_tctx_t *
large_prof_tctx_get(tsdn_t *tsdn, const extent_t *extent) {
return extent_prof_tctx_get(extent);
}
void
large_prof_tctx_set(tsdn_t *tsdn, extent_t *extent, prof_tctx_t *tctx) {
extent_prof_tctx_set(extent, tctx);
}
void
large_prof_tctx_reset(tsdn_t *tsdn, extent_t *extent) {
large_prof_tctx_set(tsdn, extent, (prof_tctx_t *)(uintptr_t)1U);
}