revert disabling of threading for rms_norm and norm

Author: xaedes

ggml.c

@@ -9666,7 +9666,7 @@ static void ggml_compute_forward_norm_f32(
     // TODO: optimize
     for (int64_t i03 = 0; i03 < ne03; i03++) {
         for (int64_t i02 = 0; i02 < ne02; i02++) {
-            for (int64_t i01 = ith; i01 < ne01; i01 += nth) { // i think this must not be threaded, because we need mean over all x
+            for (int64_t i01 = ith; i01 < ne01; i01 += nth) {
                 const float * x = (float *) ((char *) src0->data + i01*nb01 + i02*nb02 + i03*nb03);
 
                 ggml_float sum = 0.0;
@@ -9743,7 +9743,7 @@ static void ggml_compute_forward_rms_norm_f32(
     // TODO: optimize
     for (int64_t i03 = 0; i03 < ne03; i03++) {
         for (int64_t i02 = 0; i02 < ne02; i02++) {
-            for (int64_t i01 = ith; i01 < ne01; i01 += nth) { // i think this must not be threaded, because we need mean over all x*x
+            for (int64_t i01 = ith; i01 < ne01; i01 += nth) {
                 const float * x = (float *) ((char *) src0->data + i01*nb01 + i02*nb02 + i03*nb03);
 
                 ggml_float sum = 0.0;
@@ -9823,7 +9823,7 @@ static void ggml_compute_forward_rms_norm_back_f32(
     // TODO: optimize
     for (int64_t i03 = 0; i03 < ne03; i03++) {
         for (int64_t i02 = 0; i02 < ne02; i02++) {
-            for (int64_t i01 = ith; i01 < ne01; i01 += nth) { // i think this must not be threaded, because we need mean over all x*x
+            for (int64_t i01 = ith; i01 < ne01; i01 += nth) {
                 // src1 is same shape as src0 => same indices
                 const auto i11 = i01;
                 const auto i12 = i02;
@@ -14537,8 +14537,7 @@ void ggml_graph_compute(struct ggml_context * ctx, struct ggml_cgraph * cgraph)
                 case GGML_OP_RMS_NORM:
                 case GGML_OP_RMS_NORM_BACK:
                     {
-                        // i think this cannot be threaded, because we need mean over all items, not just the slices each thread sees.
-                        node->n_tasks = 1;
+                        node->n_tasks = n_threads;
                     } break;
                 case GGML_OP_MUL_MAT:
                     {