From cc2a66c586569fc7b4f83b15f83929658f58b182 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Mon, 20 Apr 2026 00:32:58 +0000
Subject: [PATCH 1/3] Initial plan


From 7a5087090995be8d59e859f54488a32fef3819d0 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Mon, 20 Apr 2026 00:36:42 +0000
Subject: [PATCH 2/3] fix: remove NVLS support check from isCuMemMapAllocated
 and fix isNvlsSupported caching

Agent-Logs-Url: https://github.com/microsoft/mscclpp/sessions/f8417c19-e697-4a32-a298-9a958b9a16a1

Co-authored-by: Binyang2014 <9415966+Binyang2014@users.noreply.github.com>
---
 src/core/gpu_utils.cc | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/src/core/gpu_utils.cc b/src/core/gpu_utils.cc
index 628d2dcbf..4efe96d45 100644
--- a/src/core/gpu_utils.cc
+++ b/src/core/gpu_utils.cc
@@ -273,8 +273,8 @@ bool isNvlsSupported() {
   if (env()->forceDisableNvls) {
     return false;
   }
-  [[maybe_unused]] static bool result = false;
-  [[maybe_unused]] static bool isChecked = false;
+  static bool result = false;
+  static bool isChecked = false;
 #if (CUDA_NVLS_API_AVAILABLE)
   if (!isChecked) {
     int deviceId;
@@ -283,7 +283,9 @@ bool isNvlsSupported() {
     MSCCLPP_CUDATHROW(cudaGetDevice(&deviceId));
     MSCCLPP_CUTHROW(cuDeviceGet(&dev, deviceId));
     MSCCLPP_CUTHROW(cuDeviceGetAttribute(&isMulticastSupported, CU_DEVICE_ATTRIBUTE_MULTICAST_SUPPORTED, dev));
-    return isMulticastSupported == 1;
+    result = (isMulticastSupported == 1);
+    isChecked = true;
+    return result;
   }
   return result;
 #endif
@@ -300,9 +302,6 @@ bool isCuMemMapAllocated([[maybe_unused]] void* ptr) {
     return false;
   }
   MSCCLPP_CUTHROW(cuMemRelease(handle));
-  if (!isNvlsSupported()) {
-    throw Error("cuMemMap is used in env without NVLS support", ErrorCode::InvalidUsage);
-  }
   return true;
 #endif
 }

From 6d64528defcf0959fa10bdd74cdcf2daef204fc4 Mon Sep 17 00:00:00 2001
From: "copilot-swe-agent[bot]" <198982749+Copilot@users.noreply.github.com>
Date: Mon, 20 Apr 2026 00:44:30 +0000
Subject: [PATCH 3/3] fix: restore [[maybe_unused]] on static vars in
 isNvlsSupported for HIP env

Agent-Logs-Url: https://github.com/microsoft/mscclpp/sessions/dc2eb9a6-b5e4-4daf-8c7d-c6eac8223dff

Co-authored-by: Binyang2014 <9415966+Binyang2014@users.noreply.github.com>
---
 src/core/gpu_utils.cc | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/core/gpu_utils.cc b/src/core/gpu_utils.cc
index 4efe96d45..09d5025d6 100644
--- a/src/core/gpu_utils.cc
+++ b/src/core/gpu_utils.cc
@@ -273,8 +273,8 @@ bool isNvlsSupported() {
   if (env()->forceDisableNvls) {
     return false;
   }
-  static bool result = false;
-  static bool isChecked = false;
+  [[maybe_unused]] static bool result = false;
+  [[maybe_unused]] static bool isChecked = false;
 #if (CUDA_NVLS_API_AVAILABLE)
   if (!isChecked) {
     int deviceId;