[Deterministic] Support Qwen3-Next model deterministic inference (#13100)

python/sglang/srt/mem_cache/memory_pool.py

@@ -297,6 +297,15 @@ class MambaPool:
         self.mamba_cache.temporal[:, free_index] = 0
 
     def clear(self):
+        # Zero the entire mamba cache before resetting free_slots
+        # This ensures that when slots are reallocated, they start with clean state
+        if self.is_kda_cache:
+            for i in range(len(self.mamba_cache.conv)):
+                self.mamba_cache.conv[i].zero_()
+        else:
+            self.mamba_cache.conv.zero_()
+        self.mamba_cache.temporal.zero_()
+
         self.free_slots = torch.arange(self.size, dtype=torch.int64, device=self.device)
 
     def copy_from(self, src_index: torch.Tensor, dst_index: torch.Tensor):