Revert "Fixing issue when setting up the number of stock GC threads - it should be 0 when using MMTk"

This reverts commit e591ad8.

Author: qinsoon

src/mmtk-gc.c

@@ -350,9 +350,6 @@ void jl_gc_init(void)
         max_heap_size = uv_get_free_memory() * 70 / 100;
     }
 
-    // when using mmtk, we don't spawn any stock GC thread
-    // and mmtk should use jl_options.ngcthreads to set the number of workers
-    assert(jl_n_gcthreads == 0);
 
     // Check that the julia_copy_stack rust feature has been defined when the COPY_STACK has been defined
     int copy_stacks;

src/threading.c

@@ -694,12 +694,6 @@ void jl_init_threading(void)
     }
     int16_t ngcthreads = jl_n_markthreads + jl_n_sweepthreads;
 
-#ifdef MMTK_GC
-    // MMTk gets the number of GC threads from jl_options.ngcthreads, and spawn its GC threads.
-    // So we just set ngcthreads to 0 here to avoid spawning any GC threads in Julia.
-    ngcthreads = 0;
-#endif
-
     jl_all_tls_states_size = nthreads + nthreadsi + ngcthreads;
     jl_n_threads_per_pool = (int*)malloc_s(2 * sizeof(int));
     jl_n_threads_per_pool[0] = nthreadsi;
@@ -717,6 +711,11 @@ void jl_start_threads(void)
 {
     int nthreads = jl_atomic_load_relaxed(&jl_n_threads);
     int ngcthreads = jl_n_gcthreads;
+#ifdef MMTK_GC
+    // MMTk gets the number of GC threads from jl_options.ngcthreads, and spawn its GC threads.
+    // So we just set ngcthreads to 0 here to avoid spawning any GC threads in Julia.
+    ngcthreads = 0;
+#endif
     int cpumasksize = uv_cpumask_size();
     char *cp;
     int i, exclusive;