gc_ms: skip counting num_free_objects unless GC_STATS (debugging only)

parrot · Jan 23, 2015 · 53139d9 · 53139d9
1 parent 68c7dac
commit 53139d9
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Showing 3 changed files with 47 additions and 10 deletions.
diff --git a/src/gc/fixed_allocator.c b/src/gc/fixed_allocator.c
@@ -419,6 +419,7 @@ Static implementation of public methods.
 
 */
 
+PARROT_INLINE
 PARROT_CANNOT_RETURN_NULL
 static void *
 get_free_list_item(ARGMOD(Pool_Allocator *pool))
@@ -427,7 +428,9 @@ get_free_list_item(ARGMOD(Pool_Allocator *pool))
 
     Pool_Allocator_Free_List * const item = pool->free_list;
     pool->free_list = item->next;
+#ifdef GC_STATS
     --pool->num_free_objects;
+#endif
     return item;
 }
 
@@ -446,20 +449,24 @@ pool_allocate(PARROT_INTERP, ARGMOD(Pool_Allocator *pool))
     return get_newfree_list_item(pool);
 }
 
+PARROT_INLINE
 PARROT_CANNOT_RETURN_NULL
 static void *
 get_newfree_list_item(ARGMOD(Pool_Allocator *pool))
 {
     ASSERT_ARGS(get_newfree_list_item)
 
     Pool_Allocator_Free_List * const item = pool->newfree;
+#ifdef GC_STATS
+    --pool->num_free_objects;
+#endif
     pool->newfree = (Pool_Allocator_Free_List *)
                     ((char *)(pool->newfree) + pool->object_size);
 
-    --pool->num_free_objects;
     return item;
 }
 
+PARROT_INLINE
 static void
 pool_free(SHIM_INTERP, ARGMOD(Pool_Allocator *pool), ARGMOD(void *data))
 {
@@ -473,9 +480,12 @@ pool_free(SHIM_INTERP, ARGMOD(Pool_Allocator *pool), ARGMOD(void *data))
     item->next      = pool->free_list;
     pool->free_list = item;
 
+#ifdef GC_STATS
     ++pool->num_free_objects;
+#endif
 }
 
+PARROT_INLINE
 PARROT_WARN_UNUSED_RESULT
 PARROT_PURE_FUNCTION
 static int
@@ -490,6 +500,7 @@ pool_is_maybe_owned(ARGIN(const Pool_Allocator *pool), ARGIN(const void *ptr))
     return (ptr >= pool->lo_arena_ptr && ptr < pool->hi_arena_ptr);
 }
 
+PARROT_INLINE
 PARROT_WARN_UNUSED_RESULT
 static int
 pool_is_owned(ARGIN(const Pool_Allocator *pool), ARGIN(const void *ptr))
@@ -500,8 +511,8 @@ pool_is_owned(ARGIN(const Pool_Allocator *pool), ARGIN(const void *ptr))
         int p;
 
         for (p = 0; p < pool->num_arenas; p++) {
-            const size_t idx = 2 * p;
-            void * const low = pool->arena_bounds[idx];
+            const size_t idx  = 2 * p;
+            void * const low  = pool->arena_bounds[idx];
             void * const high = pool->arena_bounds[idx + 1];
             if (ptr >= low && ptr < high) {
                 const ptrdiff_t ptrdiff = (const char *)ptr - (const char *)low;
@@ -551,8 +562,9 @@ allocate_new_pool_arena(PARROT_INTERP, ARGMOD(Pool_Allocator *pool))
     pool->newfree   = next;
     pool->newlast   = last;
 
+#ifdef GC_STATS
     pool->num_free_objects += num_items;
-
+#endif
     if (pool->lo_arena_ptr > (void *)next)
         pool->lo_arena_ptr = next;
 

diff --git a/src/gc/gc_ms.c b/src/gc/gc_ms.c
@@ -1,5 +1,5 @@
 /*
-Copyright (C) 2001-2014, Parrot Foundation.
+Copyright (C) 2001-2015, Parrot Foundation.
 
 =head1 NAME
 
@@ -633,11 +633,9 @@ gc_ms_mark_and_sweep(PARROT_INTERP, UINTVAL flags)
            function to the PMC pool and all the sized pools. */
        header_pools_iterate_callback(interp, mem_pools,
             POOL_BUFFER | POOL_PMC, (void *)&total_free, gc_ms_sweep_cb);
-
     }
     else {
         ++interp->gc_sys->stats.gc_lazy_mark_runs;
-
         Parrot_gc_clear_live_bits(interp, mem_pools->pmc_pool);
     }
 
@@ -838,7 +836,9 @@ gc_ms_free_pmc_header(PARROT_INTERP, ARGMOD(PMC *pmc))
 
     PObj_flags_SETTO((PObj *)pmc, PObj_on_free_list_FLAG);
     pool->add_free_object(interp, mem_pools, pool, (PObj *)pmc);
+#ifdef GC_STATS
     ++pool->num_free_objects;
+#endif
 }
 
 /*
@@ -967,7 +967,9 @@ gc_ms_free_string_header(PARROT_INTERP, ARGMOD(STRING *s))
         Fixed_Size_Pool * const pool = mem_pools->string_header_pool;
         PObj_flags_SETTO((PObj *)s, PObj_on_free_list_FLAG);
         pool->add_free_object(interp, mem_pools, pool, s);
+#ifdef GC_STATS
         ++pool->num_free_objects;
+#endif
     }
 }
 
@@ -1100,7 +1102,9 @@ Parrot_gc_get_attributes_from_pool(PARROT_INTERP, ARGMOD(PMC_Attribute_Pool * po
         return Parrot_gc_get_attributes_from_pool(interp, pool);
     }
 
+#ifdef GC_STATS
     --pool->num_free_objects; /* the hottest op in --gc ms: 11.64% */
+#endif
     return (void *)item;
 }
 
@@ -1127,7 +1131,9 @@ Parrot_gc_allocate_new_attributes_arena(ARGMOD(PMC_Attribute_Pool *pool))
     pool->newfree   = next;
     pool->newlast   = (PMC_Attribute_Free_List *)((char *)next + item_space);
 
+#ifdef GC_STATS
     pool->num_free_objects += num_items;
+#endif
     pool->total_objects    += num_items;
 }
 
@@ -1198,7 +1204,9 @@ Parrot_gc_create_attrib_pool(size_t attrib_idx)
     newpool->attr_size         = attrib_size;
     newpool->total_objects     = 0;
     newpool->objects_per_alloc = num_objs;
+#ifdef GC_STATS
     newpool->num_free_objects  = 0;
+#endif
     newpool->free_list         = NULL;
     newpool->top_arena         = NULL;
 
@@ -1313,7 +1321,9 @@ gc_ms_free_attributes_from_pool(ARGMOD(PMC_Attribute_Pool *pool), ARGMOD(void *d
     item->next      = pool->free_list;
     pool->free_list = item;
 
+#ifdef GC_STATS
     ++pool->num_free_objects;
+#endif
 }
 
 /*
@@ -1507,8 +1517,9 @@ gc_ms_sweep_cb(PARROT_INTERP,
 
     Parrot_gc_sweep_pool(interp, mem_pools, pool);
 
+#ifdef GC_STATS
     *total_free += pool->num_free_objects;
-
+#endif
     return 0;
 }
 
@@ -1567,8 +1578,9 @@ gc_ms_more_traceable_objects(PARROT_INTERP,
          &&  Parrot_gc_ms_needed(interp)))
             Parrot_gc_mark_and_sweep(interp, GC_trace_stack_FLAG);
 
-    /* requires that num_free_objects be updated in Parrot_gc_mark_and_sweep.
-       If gc is disabled, then we must check the free list directly. */
+    /* Requires that num_free_objects be updated in Parrot_gc_mark_and_sweep.
+       Keeping num_free_objects is expensive, so we disable it with --optimize.
+       Also if gc is disabled, then we must check the free list directly. */
     if ((!pool->free_list || pool->num_free_objects < pool->replenish_level)
         && !pool->newfree)
         (*pool->alloc_objects) (interp, mem_pools, pool);

diff --git a/src/gc/gc_private.h b/src/gc/gc_private.h
@@ -25,6 +25,17 @@ Parrot.
 #include "parrot/settings.h"
 #include "variable_size_pool.h"
 
+/* Do not calculate private gc statistics, only used in gc_ms.
+   Currently skipped: num_free_objects.
+ */
+#ifndef GC_STATS
+#  ifdef NDEBUG
+#    undef GC_STATS
+#  else
+#    define GC_STATS
+#  endif
+#endif
+
 #if ! DISABLE_GC_DEBUG
 /* Set when walking the system stack. Defined in src/gc/system.c */
 extern int CONSERVATIVE_POINTER_CHASING;
@@ -316,7 +327,9 @@ typedef struct PMC_Attribute_Pool {
     size_t attr_size;                    /* Size of attribute object. */
     size_t total_objects;                /* Total objects in the pool. */
     size_t objects_per_alloc;            /* Number of object slots to allocate. */
+#ifdef GC_STATS
     size_t num_free_objects;             /* Number of objects on the free list. */
+#endif
     PMC_Attribute_Free_List * free_list; /* List of free object slots, or NULL. */
     PMC_Attribute_Arena     * top_arena; /* Pointer to most recent arena. */
     PMC_Attribute_Free_List * newfree;   /* Pointer to next object slot in