From 0be8a0af0ef2d1c740dc4d084f368e75ef55a2cf Mon Sep 17 00:00:00 2001
From: Shuwen Wang <47200617+alphabetc1@users.noreply.github.com>
Date: Fri, 18 Sep 2026 15:06:35 +0800
Subject: [PATCH] [DSV4] fix: keep the TileLang JIT cache under
 SGLANG_CACHE_DIR (#39364)

---
 python/sglang/srt/entrypoints/engine.py | 1 +
 python/sglang/srt/environ.py            | 4 ++++
 2 files changed, 5 insertions(+)

diff --git a/python/sglang/srt/entrypoints/engine.py b/python/sglang/srt/entrypoints/engine.py
index 3b4eb790b..fecbc573f 100644
--- a/python/sglang/srt/entrypoints/engine.py
+++ b/python/sglang/srt/entrypoints/engine.py
@@ -1784,6 +1784,7 @@ def _log_legacy_kernel_cache_dirs():
             os.path.expanduser("~/.triton"),
             os.path.expanduser("~/.cache/flashinfer"),
             os.path.expanduser("~/.cache/deep_gemm"),
+            os.path.expanduser("~/.tilelang/cache"),
         )
         if os.path.isdir(d)
     ]
diff --git a/python/sglang/srt/environ.py b/python/sglang/srt/environ.py
index c71c22d50..a84f362fa 100644
--- a/python/sglang/srt/environ.py
+++ b/python/sglang/srt/environ.py
@@ -1948,6 +1948,10 @@ def third_party_cache_defaults() -> Dict[str, str]:
         "TRITON_CACHE_DIR": os.path.join(base, "triton"),
         "TORCHINDUCTOR_CACHE_DIR": os.path.join(base, "inductor"),
         "CUDA_CACHE_PATH": os.path.join(base, "nv"),
+        # TileLang compiles the DeepSeek-V4 MHC prenorm kernels; left at its own
+        # default the burst is invisible to anyone warming, mounting or baking
+        # SGLANG_CACHE_DIR, and gets paid again on every cold container.
+        "TILELANG_CACHE_DIR": os.path.join(base, "tilelang"),
         # FlashInfer appends ".cache/flashinfer" to this base itself, so this
         # is the base dir rather than the final cache dir.
         "FLASHINFER_WORKSPACE_BASE": base,