[release-1.11] fix GC race bug in pool sweep

JuliaLang · Aug 13, 2024 · b46f879 · b46f879
1 parent 34c3a63
commit b46f879
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Showing 2 changed files with 3 additions and 4 deletions.
diff --git a/src/gc.c b/src/gc.c
@@ -1430,7 +1430,7 @@ STATIC_INLINE void gc_dump_page_utilization_data(void) JL_NOTSAFEPOINT
     }
 }
 
-int64_t buffered_pages = 0;
+_Atomic(int64_t) buffered_pages = 0;
 
 // Returns pointer to terminal pointer of list rooted at *pfl.
 static void gc_sweep_page(gc_page_profiler_serializer_t *s, jl_gc_pool_t *p, jl_gc_page_stack_t *allocd, jl_gc_page_stack_t *buffered,
@@ -1461,8 +1461,8 @@ static void gc_sweep_page(gc_page_profiler_serializer_t *s, jl_gc_pool_t *p, jl_
         // the eager one uses less memory.
         // FIXME - need to do accounting on a per-thread basis
         // on quick sweeps, keep a few pages empty but allocated for performance
-        if (!current_sweep_full && buffered_pages <= default_collect_interval / GC_PAGE_SZ) {
-            buffered_pages++;
+        if (!current_sweep_full && jl_atomic_load_relaxed(&buffered_pages) <= default_collect_interval / GC_PAGE_SZ) {
+            jl_atomic_fetch_add_relaxed(&buffered_pages, 1);
             keep_as_local_buffer = 1;
         }
     #endif

diff --git a/src/gc.h b/src/gc.h
@@ -441,7 +441,6 @@ extern jl_gc_num_t gc_num;
 extern bigval_t *big_objects_marked;
 extern arraylist_t finalizer_list_marked;
 extern arraylist_t to_finalize;
-extern int64_t buffered_pages;
 extern int gc_first_tid;
 extern int gc_n_threads;
 extern jl_ptls_t* gc_all_tls_states;