training mode working too got from 2 toks/sec to 30 toks/sec with raw 1.5B model

llms/mlx_lm/tuner/grpo_trainer.py

@@ -112,51 +112,90 @@ def r1_count_xml(prompts: list, completions: list, answer: list, **kwargs) -> li
     return scores
     
 
-def generate_grpo(model: nn.Module, prompts, max_tokens, tokenizer, group_size):
+def generate_grpo(model: nn.Module, prompts, max_tokens, tokenizer, group_size, is_training=False):
     if len(prompts.shape) == 1:
         prompts = prompts[None, :]
     if prompts.shape[1] == 0:
         return None
 
-    model.eval()
     batch_size = prompts.shape[0] * group_size
     expanded_prompts = mx.repeat(prompts, group_size, axis=0)
+    mx.eval(expanded_prompts)
     
     results = []
     tokens_generated = 0
     start_time = time.perf_counter()
 
-    try:
     for idx in range(batch_size):
-            current_tokens = []
+        current_prompt = expanded_prompts[idx:idx+1]
-            generator = generate_step(
+        mx.eval(current_prompt)
-                expanded_prompts[idx],
-                model,
-                max_tokens=max_tokens,
-                sampler=lambda x: mx.argmax(x, axis=-1)
-            )
         
-            # Collect all tokens first
+        current_tokens = []
-            for tokens, _ in generator:
+        try:
-                current_tokens.append(tokens)
+            if is_training:
+                # Initialize with prompt
+                current_input = current_prompt[0]
+                mx.eval(current_input)
+                
+                while len(current_tokens) < max_tokens:
+                    # Generate one token at a time
+                    logits = model(current_input[None])
+                    next_token = mx.random.categorical(logits[:, -1, :])
+                    token = next_token.item()
+                    current_tokens.append(token)
                     tokens_generated += 1
-                if tokens == tokenizer.eos_token_id:
+                    
+                    # Clear intermediate results
+                    mx.eval(next_token)
+                    del logits
+                    
+                    if token == tokenizer.eos_token_id:
                         break
                         
-            # Convert to array after collection
+                    # Update input for next iteration
-            results.append(mx.array(current_tokens))
+                    current_input = mx.array([token])
-            mx.metal.clear_cache()
+                    mx.eval(current_input)
                     
-        # Final evaluation of all results
+                    # Clear cache periodically
-        mx.eval(results)
+                    if len(current_tokens) % 8 == 0:
-        generation_time = time.perf_counter() - start_time
+                        mx.metal.clear_cache()
-        print(f"Generated {tokens_generated} tokens in {generation_time:.2f}s ({tokens_generated/generation_time:.2f} tokens/s)")
+            else:
-        return results
+                generator = generate_step(
+                    current_prompt[0],
+                    model,
+                    max_tokens=max_tokens,
+                    sampler=lambda x: mx.random.categorical(x)
+                )
+                
+                for token, _ in generator:
+                    current_tokens.append(token)
+                    tokens_generated += 1
+                    if token == tokenizer.eos_token_id:
+                        break
+            
+            if current_tokens:
+                token_array = mx.array(current_tokens)
+                mx.eval(token_array)
+                results.append(token_array)
+                del token_array
             
         except Exception as e:
-        print(f"Generation error: {str(e)}")
+            print(f"Generation failed for sequence {idx}: {e}")
+            continue
+
+        mx.metal.clear_cache()
+
+    if not results:
+        print("No successful generations")
         return None
 
+    mx.eval(results)
+    
+    generation_time = time.perf_counter() - start_time
+    print(f"Generated {tokens_generated} tokens in {generation_time:.2f}s ({tokens_generated/generation_time:.2f} tokens/s)")
+    
+    return results
+
 
 def get_per_token_logps(model: nn.Module, inputs, lengths):
     logits = model(inputs).astype(mx.float16)
@@ -209,7 +248,8 @@ def grpo_loss(
                 prompt_tensor, 
                 max_tokens, 
                 tokenizer,
-                group_size
+                group_size,
+                True
             )
             
             if completions is not None:
@@ -222,6 +262,8 @@ def grpo_loss(
             print(f"Generation error: {e}")
             continue
     
+    mx.metal.clear_cache()
+
     expanded_answers = []
     expanded_prompts = []
     for i in range(batch_size):