ruby-changes:71590
From: Matt <ko1@a...>
Date: Fri, 1 Apr 2022 21:46:13 +0900 (JST)
Subject: [ruby-changes:71590] c26a85fc96 (master): [Feature #18619] Remove redundant compaction path
https://git.ruby-lang.org/ruby.git/commit/?id=c26a85fc96 From c26a85fc968d19fc40b9aee8fb8451a08e3d26d1 Mon Sep 17 00:00:00 2001 From: Matt Valentine-House <matt@e...> Date: Thu, 31 Mar 2022 20:39:17 +0100 Subject: [Feature #18619] Remove redundant compaction path --- gc.c | 206 +------------------------------------------------------------------ 1 file changed, 2 insertions(+), 204 deletions(-) diff --git a/gc.c b/gc.c index cf0a70306a..66e04d4a21 100644 --- a/gc.c +++ b/gc.c @@ -5004,46 +5004,8 @@ unlock_page_body(rb_objspace_t *objspace, struct heap_page_body *body) https://github.com/ruby/ruby/blob/trunk/gc.c#L5004 } } -static inline bool -try_move_plane(rb_objspace_t *objspace, rb_heap_t *heap, struct heap_page *page, uintptr_t p, bits_t bits, VALUE dest) -{ - if (bits) { - do { - if (bits & 1) { - /* We're trying to move "p" */ - objspace->rcompactor.considered_count_table[BUILTIN_TYPE((VALUE)p)]++; - - if (gc_is_moveable_obj(objspace, (VALUE)p)) { - /* We were able to move "p" */ - objspace->rcompactor.moved_count_table[BUILTIN_TYPE((VALUE)p)]++; - objspace->rcompactor.total_moved++; - - bool from_freelist = false; - - if (BUILTIN_TYPE(dest) == T_NONE) { - from_freelist = true; - } - - gc_move(objspace, (VALUE)p, dest, page->slot_size); - gc_pin(objspace, (VALUE)p); - heap->compact_cursor_index = p; - if (from_freelist) { - FL_SET((VALUE)p, FL_FROM_FREELIST); - } - - return true; - } - } - p += BASE_SLOT_SIZE; - bits >>= 1; - } while (bits); - } - - return false; -} - static bool -try_move2(rb_objspace_t *objspace, rb_heap_t *heap, struct heap_page *free_page, VALUE src) +try_move(rb_objspace_t *objspace, rb_heap_t *heap, struct heap_page *free_page, VALUE src) { if (!free_page) { return false; @@ -5070,7 +5032,6 @@ try_move2(rb_objspace_t *objspace, rb_heap_t *heap, struct heap_page *free_page, https://github.com/ruby/ruby/blob/trunk/gc.c#L5032 objspace->rcompactor.moved_count_table[BUILTIN_TYPE(src)]++; objspace->rcompactor.total_moved++; - //fprintf(stderr, "\t\tMoving objects: %s\n\t\t\t-> %s\n", obj_info(src), obj_info(dest)); gc_move(objspace, src, dest, free_page->slot_size); gc_pin(objspace, src); FL_SET(src, FL_FROM_FREELIST); @@ -5080,76 +5041,6 @@ try_move2(rb_objspace_t *objspace, rb_heap_t *heap, struct heap_page *free_page, https://github.com/ruby/ruby/blob/trunk/gc.c#L5041 return true; } -static short -try_move(rb_objspace_t *objspace, rb_heap_t *heap, struct heap_page *sweep_page, VALUE dest) -{ - struct heap_page * cursor = heap->compact_cursor; - - GC_ASSERT(!MARKED_IN_BITMAP(GET_HEAP_MARK_BITS(dest), dest)); - - /* T_NONE objects came from the free list. If the object is *not* a - * T_NONE, it is an object that just got freed but hasn't been - * added to the freelist yet */ - - while (1) { - size_t index; - - bits_t *mark_bits = cursor->mark_bits; - bits_t *pin_bits = cursor->pinned_bits; - uintptr_t p; - - if (heap->compact_cursor_index) { - index = BITMAP_INDEX(heap->compact_cursor_index); - p = heap->compact_cursor_index; - GC_ASSERT(cursor == GET_HEAP_PAGE(p)); - } - else { - index = 0; - p = cursor->start; - } - - bits_t bits = mark_bits[index] & ~pin_bits[index]; - - int plane_offset = NUM_IN_PAGE(p) % BITS_BITLENGTH; - bits >>= plane_offset; - if (try_move_plane(objspace, heap, sweep_page, p, bits, dest)) return 1; - - p += (BITS_BITLENGTH - plane_offset) * BASE_SLOT_SIZE; - - /* Find an object to move and move it. Movable objects must be - * marked, so we iterate using the marking bitmap */ - for (size_t i = index + 1; i < HEAP_PAGE_BITMAP_LIMIT; i++) { - bits_t bits = mark_bits[i] & ~pin_bits[i]; - if (try_move_plane(objspace, heap, sweep_page, p, bits, dest)) return 1; - p += BITS_BITLENGTH * BASE_SLOT_SIZE; - } - - /* We couldn't find a movable object on the compact cursor, so lets - * move to the next page (previous page since we are traveling in the - * opposite direction of the sweep cursor) and look there. */ - - struct heap_page * next; - - next = ccan_list_prev(&heap->pages, cursor, page_node); - - /* Protect the current cursor since it probably has T_MOVED slots. */ - lock_page_body(objspace, GET_PAGE_BODY(cursor->start)); - - heap->compact_cursor = next; - heap->compact_cursor_index = 0; - cursor = next; - - // Cursors have met, lets quit. We set `heap->compact_cursor` equal - // to `heap->sweeping_page` so we know how far to iterate through - // the heap when unprotecting pages. - if (next == sweep_page) { - break; - } - } - - return 0; -} - static void gc_unprotect_pages(rb_objspace_t *objspace, rb_heap_t *heap) { @@ -5374,99 +5265,6 @@ struct gc_sweep_context { https://github.com/ruby/ruby/blob/trunk/gc.c#L5265 int empty_slots; }; -static inline void -gc_fill_swept_plane(rb_objspace_t *objspace, rb_heap_t *heap, uintptr_t p, bits_t bitset, bool *finished_compacting, struct gc_sweep_context *ctx) -{ - struct heap_page * sweep_page = ctx->page; - - if (bitset) { - short slot_size = sweep_page->slot_size; - short slot_bits = slot_size / BASE_SLOT_SIZE; - - do { - if (bitset & 1) { - VALUE dest = (VALUE)p; - - GC_ASSERT(MARKED_IN_BITMAP(GET_HEAP_PINNED_BITS(dest), dest)); - GC_ASSERT(!MARKED_IN_BITMAP(GET_HEAP_MARK_BITS(dest), dest)); - - CLEAR_IN_BITMAP(GET_HEAP_PINNED_BITS(dest), dest); - - if (*finished_compacting) { - if (BUILTIN_TYPE(dest) == T_NONE) { - ctx->empty_slots++; - } - else { - ctx->freed_slots++; - } - (void)VALGRIND_MAKE_MEM_UNDEFINED((void*)dest, BASE_SLOT_SIZE); - heap_page_add_freeobj(objspace, sweep_page, dest); - } - else { - /* Zombie slots don't get marked, but we can't reuse - * their memory until they have their finalizers run.*/ - if (BUILTIN_TYPE(dest) != T_ZOMBIE) { - if (!try_move(objspace, heap, sweep_page, dest)) { - *finished_compacting = true; - (void)VALGRIND_MAKE_MEM_UNDEFINED((void*)p, BASE_SLOT_SIZE); - gc_report(5, objspace, "Quit compacting, couldn't find an object to move\n"); - if (BUILTIN_TYPE(dest) == T_NONE) { - ctx->empty_slots++; - } - else { - ctx->freed_slots++; - } - heap_page_add_freeobj(objspace, sweep_page, dest); - gc_report(3, objspace, "page_sweep: %s is added to freelist\n", obj_info(dest)); - } - else { - //moved_slots++; - } - } - } - } - p += slot_size; - bitset >>= slot_bits; - } while (bitset); - } -} - -static bool -gc_fill_swept_page(rb_objspace_t *objspace, rb_heap_t *heap, struct heap_page *sweep_page, struct gc_sweep_context *ctx) -{ - /* Find any pinned but not marked objects and try to fill those slots */ - bool finished_compacting = false; - bits_t *mark_bits, *pin_bits; - bits_t bitset; - uintptr_t p; - - mark_bits = sweep_page->mark_bits; - pin_bits = sweep_page->pinned_bits; - - p = (uintptr_t)sweep_page->start; - - struct heap_page * cursor = heap->compact_cursor; - - unlock_page_body(objspace, GET_PAGE_BODY(cursor->start)); - - /* *Want to move* objects are pinned but not marked. */ - bitset = pin_bits[0] & ~mark_bits[0]; - bitset >>= NUM_IN_PAGE(p); // Skip header / dead space bits - gc_fill_swept_plane(objspace, heap, (uintptr_t)p, bitset, &finished_compacting, ctx); - p += ((BITS_BITLENGTH - NUM_IN_PAGE(p)) * BASE_SLOT_SIZE); - - for (int i = 1; i < HEAP_PAGE_BITMAP_LIMIT; i++) { - /* *Want to move* objects are pinned but not marked. */ - bitset = pin_bits[i] & ~mark_bits[i]; - gc_fill_swept_plane(objspace, heap, (uintptr_t)p, bitset, &finished_compacting, ctx); - p += ((BITS_BITLENGTH) * BASE_SLOT_SIZE); - } - - lock_page_body(objspace, GET_PAGE_BODY(heap->compact_cursor->start)); - - return finished_compacting; -} - static inline void gc_sweep_plane(rb_objspace_t *objspace, rb_heap_t *heap, uintptr_t p, bits_t bitset, struct gc_sweep_context *ctx) { @@ -8294,7 +8092,7 @@ gc_compact_move(rb_objspace_t *objspace, rb_heap_t *heap, VALUE src) https://github.com/ruby/ruby/blob/trunk/gc.c#L8092 if (gc_compact_heap_cursors_met_p(dheap)) { return false; } - while (!try_move2(objspace, dheap, dheap->free_pages, src)) { + while (!try_move(objspace, dheap, dheap->free_pages, src)) { struct gc_sweep_context ctx = { .page = dheap->sweeping_page, .final_slots = 0, -- cgit v1.2.1 -- ML: ruby-changes@q... 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