use field to indicate in oldest generation of bigvals

Author: d-netto

src/gc.c

@@ -984,6 +984,7 @@ STATIC_INLINE jl_value_t *jl_gc_big_alloc_inner(jl_ptls_t ptls, size_t sz)
     memset(v, 0xee, allocsz);
 #endif
     v->sz = allocsz;
+    v->in_oldest_generation_of_bigvals = 0;
     gc_big_object_link(&ptls->heap.young_generation_of_bigvals, v);
     return jl_valueof(&v->header);
 }
@@ -1038,6 +1039,7 @@ static void sweep_big_list_of_young_bigvals(bigval_t **young, bigval_t **old) JL
                 // reached oldest generation, move from young list to old list
                 gc_big_object_unlink(young, v);
                 gc_big_object_link(old, v);
+                v->in_oldest_generation_of_bigvals = 1;
             }
             v->bits.gc = bits;
         }
@@ -1049,14 +1051,17 @@ static void sweep_big_list_of_young_bigvals(bigval_t **young, bigval_t **old) JL
     }
 }
 
-static void sweep_big_list_of_oldest_bigvals(bigval_t **old) JL_NOTSAFEPOINT
+static void sweep_big_list_of_oldest_bigvals(bigval_t **young, bigval_t **old) JL_NOTSAFEPOINT
 {
     bigval_t *v = *old;
     while (v != NULL) {
         bigval_t *nxt = v->next;
         int bits = v->bits.gc;
         int old_bits = bits;
         if (gc_marked(bits)) {
+            gc_big_object_unlink(old, v);
+            gc_big_object_link(young, v);
+            v->in_oldest_generation_of_bigvals = 0;
             v->bits.gc = GC_OLD;
         }
         else {
@@ -1082,7 +1087,8 @@ static void sweep_big(jl_ptls_t ptls) JL_NOTSAFEPOINT
         for (int i = 0; i < gc_n_threads; i++) {
             jl_ptls_t ptls2 = gc_all_tls_states[i];
             if (ptls2 != NULL) {
-                sweep_big_list_of_oldest_bigvals(&ptls2->heap.oldest_generation_of_bigvals);
+                sweep_big_list_of_oldest_bigvals(&ptls2->heap.young_generation_of_bigvals,
+                                                 &ptls2->heap.oldest_generation_of_bigvals);
             }
         }
     }
@@ -4331,7 +4337,7 @@ jl_value_t *jl_gc_realloc_string(jl_value_t *s, size_t sz)
     jl_ptls_t ptls = jl_current_task->ptls;
     maybe_collect(ptls); // don't want this to happen during jl_gc_managed_realloc
     bigval_t **p_head;
-    if (hdr->bits.gc == GC_OLD_MARKED) {
+    if (hdr->in_oldest_generation_of_bigvals) {
         p_head = &ptls->heap.oldest_generation_of_bigvals;
     }
     else {

src/gc.h

@@ -126,12 +126,13 @@ JL_EXTENSION typedef struct _bigval_t {
     struct _bigval_t *next;
     struct _bigval_t *prev;
     size_t sz;
+    size_t in_oldest_generation_of_bigvals;
 #ifdef _P64 // Add padding so that the value is 64-byte aligned
-    // (8 pointers of 8 bytes each) - (4 other pointers in struct)
-    void *_padding[8 - 4];
+    // (8 pointers of 8 bytes each) - (5 other pointers in struct)
+    void *_padding[8 - 5];
 #else
-    // (16 pointers of 4 bytes each) - (4 other pointers in struct)
-    void *_padding[16 - 4];
+    // (16 pointers of 4 bytes each) - (5 other pointers in struct)
+    void *_padding[16 - 5];
 #endif
     //struct jl_taggedvalue_t <>;
     union {