From 0a66d4b0afe4a78a200809b7d1d3beec6c6a2a8f Mon Sep 17 00:00:00 2001
From: comfyanonymous <121283862+comfyanonymous@users.noreply.github.com>
Date: Tue, 29 Apr 2025 17:28:52 -0700
Subject: [PATCH] Per device stream counters for async offload. (#7873)

---
 comfy/model_management.py | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/comfy/model_management.py b/comfy/model_management.py
index 78317af3..44aff376 100644
--- a/comfy/model_management.py
+++ b/comfy/model_management.py
@@ -946,9 +946,9 @@ if args.async_offload:
     NUM_STREAMS = 2
     logging.info("Using async weight offloading with {} streams".format(NUM_STREAMS))
 
-stream_counter = 0
+stream_counters = {}
 def get_offload_stream(device):
-    global stream_counter
+    stream_counter = stream_counters.get(device, 0)
     if NUM_STREAMS <= 1:
         return None
 
@@ -958,6 +958,7 @@ def get_offload_stream(device):
         stream_counter = (stream_counter + 1) % len(ss)
         if is_device_cuda(device):
             ss[stream_counter].wait_stream(torch.cuda.current_stream())
+        stream_counters[device] = stream_counter
         return s
     elif is_device_cuda(device):
         ss = []
@@ -966,6 +967,7 @@ def get_offload_stream(device):
         STREAMS[device] = ss
         s = ss[stream_counter]
         stream_counter = (stream_counter + 1) % len(ss)
+        stream_counters[device] = stream_counter
         return s
     return None