From 68978f8d52547f83af76b62e5020e4dbfe0edf13 Mon Sep 17 00:00:00 2001
From: Zhiqiang Xie <xiezhq@stanford.edu>
Date: Thu, 3 Sep 2026 12:08:17 -0700
Subject: [PATCH] [Scheduler] Count the parked chunked-prefill request in the
 busy mem check (#37502)

---
 python/sglang/srt/managers/scheduler.py       |  1 +
 .../scheduler_components/invariant_checker.py | 40 ++++++++++++-------
 2 files changed, 26 insertions(+), 15 deletions(-)

diff --git a/python/sglang/srt/managers/scheduler.py b/python/sglang/srt/managers/scheduler.py
index 9c61510a6..128ba41ee 100644
--- a/python/sglang/srt/managers/scheduler.py
+++ b/python/sglang/srt/managers/scheduler.py
@@ -2293,6 +2293,7 @@ class Scheduler(
             pool_stats_observer=self.pool_stats_observer,
             get_last_batch=lambda: self.last_batch,
             get_running_batch=lambda: self.running_batch,
+            get_chunked_req=lambda: self.chunked_req,
         )
 
     def init_rank_consensus_checker(self) -> None:
diff --git a/python/sglang/srt/managers/scheduler_components/invariant_checker.py b/python/sglang/srt/managers/scheduler_components/invariant_checker.py
index e87269a72..d49db49aa 100644
--- a/python/sglang/srt/managers/scheduler_components/invariant_checker.py
+++ b/python/sglang/srt/managers/scheduler_components/invariant_checker.py
@@ -58,6 +58,9 @@ class SchedulerInvariantChecker:
     pool_stats_observer: SchedulerPoolStatsObserver
     get_last_batch: Callable
     get_running_batch: Callable
+    # The chunked-prefill request parked between chunks is in neither batch;
+    # its uncached tokens must still be counted.
+    get_chunked_req: Callable = field(default=lambda: None)
     count_req_pool_leak_warnings: int = 0
     count_memory_leak_warnings: int = 0
     recent_busy_msgs: Deque[str] = field(
@@ -262,24 +265,31 @@ class SchedulerInvariantChecker:
 
         full_uncached = 0
         swa_uncached = 0
-        for batch in batches:
-            for req in batch.reqs:
-                if not req.kv.holds_kv:
-                    continue
+        counted: set[int] = set()
+        reqs = [req for batch in batches for req in batch.reqs]
+        chunked_req = self.get_chunked_req()
+        if chunked_req is not None:
+            reqs.append(chunked_req)
+        for req in reqs:
+            if id(req) in counted:
+                continue
+            counted.add(id(req))
+            if not req.kv.holds_kv:
+                continue
 
-                allocated_len = req.kv.kv_allocated_len
-                if self.page_size > 1:
-                    allocated_len = ceil_align(allocated_len, self.page_size)
-                    assert req.kv.cache_protected_len % self.page_size == 0
+            allocated_len = req.kv.kv_allocated_len
+            if self.page_size > 1:
+                allocated_len = ceil_align(allocated_len, self.page_size)
+                assert req.kv.cache_protected_len % self.page_size == 0
 
-                full_uncached += allocated_len - req.kv.cache_protected_len
-                if self.is_hybrid_swa:
-                    swa_uncached += allocated_len - max(
-                        req.kv.cache_protected_len, req.kv.swa_evicted_seqlen
-                    )
+            full_uncached += allocated_len - req.kv.cache_protected_len
+            if self.is_hybrid_swa:
+                swa_uncached += allocated_len - max(
+                    req.kv.cache_protected_len, req.kv.swa_evicted_seqlen
+                )
 
-                if req.beam_group is not None:
-                    full_uncached += req.beam_group.extra_uncached_tokens()
+            if req.beam_group is not None:
+                full_uncached += req.beam_group.extra_uncached_tokens()
 
         return full_uncached, swa_uncached