Feature/Fix multi lora scheduler blocking issue and evict LoRA None lastly (#14795)

python/sglang/srt/managers/scheduler.py

@@ -1817,13 +1817,21 @@ class Scheduler(
         # Get requests from the waiting queue to a new prefill batch
         for req in self.waiting_queue:
 
-            if self.enable_lora and not self.tp_worker.can_run_lora_batch(
-                lora_set
-                | set([req.lora_id for req in adder.can_run_list])
-                | set([req.lora_id])
-            ):
-                self.running_batch.batch_is_full = True
-                break
+            if self.enable_lora:
+                new_lora_set = (
+                    lora_set
+                    | set([req.lora_id for req in adder.can_run_list])
+                    | set([req.lora_id])
+                )
+                if not self.tp_worker.can_run_lora_batch(new_lora_set):
+                    # If this is a LoRA request that would exceed the LoRA slot limit,
+                    # skip it and continue to try scheduling non-LoRA requests.
+                    # Non-LoRA requests (lora_id=None) share a single reserved slot
+                    # and should never cause this check to fail.
+                    if req.lora_id is not None:
+                        # Skip this LoRA request - it would trigger adapter eviction/loading
+                        # which is slow. We'll try to schedule it in a future iteration.
+                        continue
 
             running_bs = len(self.running_batch.reqs)
             if len(adder.can_run_list) >= self.get_num_allocatable_reqs(running_bs):