From a38acf716eefc5284e89a35be74229ef3545d007 Mon Sep 17 00:00:00 2001 From: Jason Evans Date: Tue, 15 Nov 2016 13:07:53 -0800 Subject: [PATCH] Add extent serial numbers. Add extent serial numbers and use them where appropriate as a sort key that is higher priority than address, so that the allocation policy prefers older extents. This resolves #147. --- include/jemalloc/internal/arena.h | 11 ++- include/jemalloc/internal/extent.h | 74 ++++++++++++++++++- include/jemalloc/internal/private_symbols.txt | 6 ++ src/arena.c | 27 ++++--- src/base.c | 12 ++- src/extent.c | 28 +++---- src/extent_dss.c | 3 +- 7 files changed, 126 insertions(+), 35 deletions(-) diff --git a/include/jemalloc/internal/arena.h b/include/jemalloc/internal/arena.h index f518c31f..28d63c68 100644 --- a/include/jemalloc/internal/arena.h +++ b/include/jemalloc/internal/arena.h @@ -130,7 +130,8 @@ struct arena_bin_s { /* * Heap of non-full slabs. This heap is used to assure that new - * allocations come from the non-full slab that is lowest in memory. + * allocations come from the non-full slab that is oldest/lowest in + * memory. */ extent_heap_t slabs_nonfull; @@ -184,6 +185,9 @@ struct arena_s { */ size_t offset_state; + /* Extent serial number generator state. */ + size_t extent_sn_next; + dss_prec_t dss_prec; /* True if a thread is currently executing arena_purge_to_limit(). */ @@ -224,8 +228,8 @@ struct arena_s { /* User-configurable extent hook functions. */ union { - extent_hooks_t *extent_hooks; - void *extent_hooks_pun; + extent_hooks_t *extent_hooks; + void *extent_hooks_pun; }; /* Cache of extent structures that were allocated via base_alloc(). */ @@ -320,6 +324,7 @@ void arena_stats_merge(tsdn_t *tsdn, arena_t *arena, unsigned *nthreads, unsigned arena_nthreads_get(arena_t *arena, bool internal); void arena_nthreads_inc(arena_t *arena, bool internal); void arena_nthreads_dec(arena_t *arena, bool internal); +size_t arena_extent_sn_next(arena_t *arena); arena_t *arena_new(tsdn_t *tsdn, unsigned ind); void arena_boot(void); void arena_prefork0(tsdn_t *tsdn, arena_t *arena); diff --git a/include/jemalloc/internal/extent.h b/include/jemalloc/internal/extent.h index 531d853c..3c5573ee 100644 --- a/include/jemalloc/internal/extent.h +++ b/include/jemalloc/internal/extent.h @@ -26,6 +26,20 @@ struct extent_s { */ size_t e_usize; + /* + * Serial number (potentially non-unique). + * + * In principle serial numbers can wrap around on 32-bit systems if + * JEMALLOC_MUNMAP is defined, but as long as comparison functions fall + * back on address comparison for equal serial numbers, stable (if + * imperfect) ordering is maintained. + * + * Serial numbers may not be unique even in the absence of wrap-around, + * e.g. when splitting an extent and assigning the same serial number to + * both resulting adjacent extents. + */ + size_t e_sn; + /* True if extent is active (in use). */ bool e_active; @@ -66,7 +80,7 @@ struct extent_s { qr(extent_t) qr_link; union { - /* Linkage for per size class address-ordered heaps. */ + /* Linkage for per size class sn/address-ordered heaps. */ phn(extent_t) ph_link; /* Linkage for arena's large and extent_cache lists. */ @@ -144,6 +158,7 @@ size_t extent_usize_get(const extent_t *extent); void *extent_before_get(const extent_t *extent); void *extent_last_get(const extent_t *extent); void *extent_past_get(const extent_t *extent); +size_t extent_sn_get(const extent_t *extent); bool extent_active_get(const extent_t *extent); bool extent_retained_get(const extent_t *extent); bool extent_zeroed_get(const extent_t *extent); @@ -157,16 +172,20 @@ void extent_addr_set(extent_t *extent, void *addr); void extent_addr_randomize(tsdn_t *tsdn, extent_t *extent, size_t alignment); void extent_size_set(extent_t *extent, size_t size); void extent_usize_set(extent_t *extent, size_t usize); +void extent_sn_set(extent_t *extent, size_t sn); void extent_active_set(extent_t *extent, bool active); void extent_zeroed_set(extent_t *extent, bool zeroed); void extent_committed_set(extent_t *extent, bool committed); void extent_slab_set(extent_t *extent, bool slab); void extent_prof_tctx_set(extent_t *extent, prof_tctx_t *tctx); void extent_init(extent_t *extent, arena_t *arena, void *addr, - size_t size, size_t usize, bool active, bool zeroed, bool committed, - bool slab); + size_t size, size_t usize, size_t sn, bool active, bool zeroed, + bool committed, bool slab); void extent_ring_insert(extent_t *sentinel, extent_t *extent); void extent_ring_remove(extent_t *extent); +int extent_sn_comp(const extent_t *a, const extent_t *b); +int extent_ad_comp(const extent_t *a, const extent_t *b); +int extent_snad_comp(const extent_t *a, const extent_t *b); #endif #if (defined(JEMALLOC_ENABLE_INLINE) || defined(JEMALLOC_EXTENT_C_)) @@ -243,6 +262,13 @@ extent_past_get(const extent_t *extent) extent_size_get(extent))); } +JEMALLOC_INLINE size_t +extent_sn_get(const extent_t *extent) +{ + + return (extent->e_sn); +} + JEMALLOC_INLINE bool extent_active_get(const extent_t *extent) { @@ -351,6 +377,13 @@ extent_usize_set(extent_t *extent, size_t usize) extent->e_usize = usize; } +JEMALLOC_INLINE void +extent_sn_set(extent_t *extent, size_t sn) +{ + + extent->e_sn = sn; +} + JEMALLOC_INLINE void extent_active_set(extent_t *extent, bool active) { @@ -388,7 +421,8 @@ extent_prof_tctx_set(extent_t *extent, prof_tctx_t *tctx) JEMALLOC_INLINE void extent_init(extent_t *extent, arena_t *arena, void *addr, size_t size, - size_t usize, bool active, bool zeroed, bool committed, bool slab) + size_t usize, size_t sn, bool active, bool zeroed, bool committed, + bool slab) { assert(addr == PAGE_ADDR2BASE(addr) || !slab); @@ -397,6 +431,7 @@ extent_init(extent_t *extent, arena_t *arena, void *addr, size_t size, extent_addr_set(extent, addr); extent_size_set(extent, size); extent_usize_set(extent, usize); + extent_sn_set(extent, sn); extent_active_set(extent, active); extent_zeroed_set(extent, zeroed); extent_committed_set(extent, committed); @@ -419,6 +454,37 @@ extent_ring_remove(extent_t *extent) qr_remove(extent, qr_link); } + +JEMALLOC_INLINE int +extent_sn_comp(const extent_t *a, const extent_t *b) +{ + size_t a_sn = extent_sn_get(a); + size_t b_sn = extent_sn_get(b); + + return ((a_sn > b_sn) - (a_sn < b_sn)); +} + +JEMALLOC_INLINE int +extent_ad_comp(const extent_t *a, const extent_t *b) +{ + uintptr_t a_addr = (uintptr_t)extent_addr_get(a); + uintptr_t b_addr = (uintptr_t)extent_addr_get(b); + + return ((a_addr > b_addr) - (a_addr < b_addr)); +} + +JEMALLOC_INLINE int +extent_snad_comp(const extent_t *a, const extent_t *b) +{ + int ret; + + ret = extent_sn_comp(a, b); + if (ret != 0) + return (ret); + + ret = extent_ad_comp(a, b); + return (ret); +} #endif #endif /* JEMALLOC_H_INLINES */ diff --git a/include/jemalloc/internal/private_symbols.txt b/include/jemalloc/internal/private_symbols.txt index 707ede3a..4560d702 100644 --- a/include/jemalloc/internal/private_symbols.txt +++ b/include/jemalloc/internal/private_symbols.txt @@ -31,6 +31,7 @@ arena_extent_cache_maybe_remove arena_extent_dalloc_large arena_extent_ralloc_large_expand arena_extent_ralloc_large_shrink +arena_extent_sn_next arena_get arena_ichoose arena_init @@ -132,6 +133,7 @@ decay_ticker_get dss_prec_names extent_active_get extent_active_set +extent_ad_comp extent_addr_get extent_addr_randomize extent_addr_set @@ -188,6 +190,10 @@ extent_slab_data_get extent_slab_data_get_const extent_slab_get extent_slab_set +extent_sn_comp +extent_sn_get +extent_sn_set +extent_snad_comp extent_split_wrapper extent_usize_get extent_usize_set diff --git a/src/arena.c b/src/arena.c index ef374d35..75a92edc 100644 --- a/src/arena.c +++ b/src/arena.c @@ -760,7 +760,7 @@ arena_purge_to_limit(tsdn_t *tsdn, arena_t *arena, size_t ndirty_limit) size_t ndirty = arena_dirty_count(tsdn, arena); assert(ndirty == arena->ndirty); } - extent_init(&purge_extents_sentinel, arena, NULL, 0, 0, false, false, + extent_init(&purge_extents_sentinel, arena, NULL, 0, 0, 0, false, false, false, false); npurge = arena_stash_dirty(tsdn, arena, &extent_hooks, ndirty_limit, @@ -1351,12 +1351,12 @@ arena_bin_lower_slab(tsdn_t *tsdn, arena_t *arena, extent_t *slab, assert(extent_slab_data_get(slab)->nfree > 0); /* - * Make sure that if bin->slabcur is non-NULL, it refers to the lowest - * non-full slab. It is okay to NULL slabcur out rather than - * proactively keeping it pointing at the lowest non-full slab. + * Make sure that if bin->slabcur is non-NULL, it refers to the + * oldest/lowest non-full slab. It is okay to NULL slabcur out rather + * than proactively keeping it pointing at the oldest/lowest non-full + * slab. */ - if (bin->slabcur != NULL && (uintptr_t)extent_addr_get(slab) < - (uintptr_t)extent_addr_get(bin->slabcur)) { + if (bin->slabcur != NULL && extent_snad_comp(bin->slabcur, slab) > 0) { /* Switch slabcur. */ if (extent_slab_data_get(bin->slabcur)->nfree > 0) arena_bin_slabs_nonfull_insert(bin, bin->slabcur); @@ -1651,6 +1651,13 @@ arena_nthreads_dec(arena_t *arena, bool internal) atomic_sub_u(&arena->nthreads[internal], 1); } +size_t +arena_extent_sn_next(arena_t *arena) +{ + + return (atomic_add_zu(&arena->extent_sn_next, 1) - 1); +} + arena_t * arena_new(tsdn_t *tsdn, unsigned ind) { @@ -1684,6 +1691,8 @@ arena_new(tsdn_t *tsdn, unsigned ind) (size_t)(uintptr_t)arena; } + arena->extent_sn_next = 0; + arena->dss_prec = extent_dss_prec_get(); arena->purging = false; @@ -1702,7 +1711,7 @@ arena_new(tsdn_t *tsdn, unsigned ind) extent_heap_new(&arena->extents_retained[i]); } - extent_init(&arena->extents_dirty, arena, NULL, 0, 0, false, false, + extent_init(&arena->extents_dirty, arena, NULL, 0, 0, 0, false, false, false, false); if (malloc_mutex_init(&arena->extents_mtx, "arena_extents", @@ -1724,8 +1733,8 @@ arena_new(tsdn_t *tsdn, unsigned ind) return (NULL); bin->slabcur = NULL; extent_heap_new(&bin->slabs_nonfull); - extent_init(&bin->slabs_full, arena, NULL, 0, 0, false, false, - false, false); + extent_init(&bin->slabs_full, arena, NULL, 0, 0, 0, false, + false, false, false); if (config_stats) memset(&bin->stats, 0, sizeof(malloc_bin_stats_t)); } diff --git a/src/base.c b/src/base.c index 9c3f36cd..4764d9c9 100644 --- a/src/base.c +++ b/src/base.c @@ -5,6 +5,7 @@ /* Data. */ static malloc_mutex_t base_mtx; +static size_t base_extent_sn_next; static extent_heap_t base_avail[NSIZES]; static extent_t *base_extents; static size_t base_allocated; @@ -37,6 +38,14 @@ base_extent_dalloc(tsdn_t *tsdn, extent_t *extent) base_extents = extent; } +static void +base_extent_init(extent_t *extent, void *addr, size_t size) +{ + size_t sn = atomic_add_zu(&base_extent_sn_next, 1) - 1; + + extent_init(extent, NULL, addr, size, 0, sn, true, true, true, false); +} + static extent_t * base_extent_alloc(tsdn_t *tsdn, size_t minsize) { @@ -74,7 +83,7 @@ base_extent_alloc(tsdn_t *tsdn, size_t minsize) base_resident += PAGE_CEILING(nsize); } } - extent_init(extent, NULL, addr, esize, 0, true, true, true, false); + base_extent_init(extent, addr, esize); return (extent); } @@ -164,6 +173,7 @@ base_boot(void) if (malloc_mutex_init(&base_mtx, "base", WITNESS_RANK_BASE)) return (true); + base_extent_sn_next = 0; for (i = 0; i < NSIZES; i++) extent_heap_new(&base_avail[i]); base_extents = NULL; diff --git a/src/extent.c b/src/extent.c index 34ac63e8..be6cadc3 100644 --- a/src/extent.c +++ b/src/extent.c @@ -177,17 +177,8 @@ extent_size_quantize_t *extent_size_quantize_ceil = JEMALLOC_N(n_extent_size_quantize_ceil); #endif -JEMALLOC_INLINE_C int -extent_ad_comp(const extent_t *a, const extent_t *b) -{ - uintptr_t a_addr = (uintptr_t)extent_addr_get(a); - uintptr_t b_addr = (uintptr_t)extent_addr_get(b); - - return ((a_addr > b_addr) - (a_addr < b_addr)); -} - /* Generate pairing heap functions. */ -ph_gen(, extent_heap_, extent_heap_t, extent_t, ph_link, extent_ad_comp) +ph_gen(, extent_heap_, extent_heap_t, extent_t, ph_link, extent_snad_comp) static void extent_heaps_insert(tsdn_t *tsdn, extent_heap_t extent_heaps[NPSIZES+1], @@ -353,8 +344,8 @@ extent_deregister(tsdn_t *tsdn, extent_t *extent) } /* - * Do first-best-fit extent selection, i.e. select the lowest extent that best - * fits. + * Do first-best-fit extent selection, i.e. select the oldest/lowest extent that + * best fits. */ static extent_t * extent_first_best_fit(tsdn_t *tsdn, arena_t *arena, @@ -708,7 +699,8 @@ extent_alloc_wrapper_hard(tsdn_t *tsdn, arena_t *arena, extent_dalloc(tsdn, arena, extent); return (NULL); } - extent_init(extent, arena, addr, size, usize, true, zero, commit, slab); + extent_init(extent, arena, addr, size, usize, + arena_extent_sn_next(arena), true, zero, commit, slab); if (pad != 0) extent_addr_randomize(tsdn, extent, alignment); if (extent_register(tsdn, extent)) { @@ -1036,7 +1028,7 @@ extent_split_wrapper(tsdn_t *tsdn, arena_t *arena, extent_t lead; extent_init(&lead, arena, extent_addr_get(extent), size_a, - usize_a, extent_active_get(extent), + usize_a, extent_sn_get(extent), extent_active_get(extent), extent_zeroed_get(extent), extent_committed_get(extent), extent_slab_get(extent)); @@ -1046,9 +1038,9 @@ extent_split_wrapper(tsdn_t *tsdn, arena_t *arena, } extent_init(trail, arena, (void *)((uintptr_t)extent_base_get(extent) + - size_a), size_b, usize_b, extent_active_get(extent), - extent_zeroed_get(extent), extent_committed_get(extent), - extent_slab_get(extent)); + size_a), size_b, usize_b, extent_sn_get(extent), + extent_active_get(extent), extent_zeroed_get(extent), + extent_committed_get(extent), extent_slab_get(extent)); if (extent_rtree_acquire(tsdn, rtree_ctx, trail, false, true, &trail_elm_a, &trail_elm_b)) goto label_error_c; @@ -1145,6 +1137,8 @@ extent_merge_wrapper(tsdn_t *tsdn, arena_t *arena, extent_size_set(a, extent_size_get(a) + extent_size_get(b)); extent_usize_set(a, extent_usize_get(a) + extent_usize_get(b)); + extent_sn_set(a, (extent_sn_get(a) < extent_sn_get(b)) ? + extent_sn_get(a) : extent_sn_get(b)); extent_zeroed_set(a, extent_zeroed_get(a) && extent_zeroed_get(b)); extent_rtree_write_acquired(tsdn, a_elm_a, b_elm_b, a); diff --git a/src/extent_dss.c b/src/extent_dss.c index 31fe8fe2..1169d496 100644 --- a/src/extent_dss.c +++ b/src/extent_dss.c @@ -142,7 +142,8 @@ extent_alloc_dss(tsdn_t *tsdn, arena_t *arena, void *new_addr, size_t size, gap_size = (uintptr_t)ret - (uintptr_t)gap_addr; if (gap_size != 0) { extent_init(gap, arena, gap_addr, gap_size, - gap_size, false, false, true, false); + gap_size, arena_extent_sn_next(arena), + false, false, true, false); } dss_next = (void *)((uintptr_t)ret + size); if ((uintptr_t)ret < (uintptr_t)max_cur ||