[Openmp-commits] [PATCH] D82718: [OpenMP] Use primary context in CUDA plugin

[Shilei Tian via Phabricator via Openmp-commits]

This revision was not accepted when it landed; it landed in state "Needs Review".
This revision was automatically updated to reflect the committed changes.
Closed by commit rGc5348aecd772: [OpenMP] Use primary context in CUDA plugin (authored by ye-luo, committed by tianshilei1992).

Changed prior to commit:
  https://reviews.llvm.org/D82718?vs=275156&id=275663#toc

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D82718/new/

https://reviews.llvm.org/D82718

Files:
  openmp/libomptarget/plugins/cuda/src/rtl.cpp


Index: openmp/libomptarget/plugins/cuda/src/rtl.cpp
===================================================================
--- openmp/libomptarget/plugins/cuda/src/rtl.cpp
+++ openmp/libomptarget/plugins/cuda/src/rtl.cpp
@@ -385,9 +385,15 @@
 
     for (DeviceDataTy &D : DeviceData) {
       // Destroy context
-      if (D.Context)
-        checkResult(cuCtxDestroy(D.Context),
-                    "Error returned from cuCtxDestroy\n");
+      if (D.Context) {
+        checkResult(cuCtxSetCurrent(D.Context),
+                    "Error returned from cuCtxSetCurrent\n");
+        CUdevice Device;
+        checkResult(cuCtxGetDevice(&Device),
+                    "Error returned from cuCtxGetDevice\n");
+        checkResult(cuDevicePrimaryCtxRelease(Device),
+                    "Error returned from cuDevicePrimaryCtxRelease\n");
+      }
     }
   }
 
@@ -408,10 +414,32 @@
     if (!checkResult(Err, "Error returned from cuDeviceGet\n"))
       return OFFLOAD_FAIL;
 
-    // Create the context and save it to use whenever this device is selected.
-    Err = cuCtxCreate(&DeviceData[DeviceId].Context, CU_CTX_SCHED_BLOCKING_SYNC,
-                      Device);
-    if (!checkResult(Err, "Error returned from cuCtxCreate\n"))
+    // Query the current flags of the primary context and set its flags if
+    // it is inactive
+    unsigned int FormerPrimaryCtxFlags = 0;
+    int FormerPrimaryCtxIsActive = 0;
+    Err = cuDevicePrimaryCtxGetState(Device, &FormerPrimaryCtxFlags,
+                                     &FormerPrimaryCtxIsActive);
+    if (!checkResult(Err, "Error returned from cuDevicePrimaryCtxGetState\n"))
+      return OFFLOAD_FAIL;
+
+    if (FormerPrimaryCtxIsActive) {
+      DP("The primary context is active, no change to its flags\n");
+      if ((FormerPrimaryCtxFlags & CU_CTX_SCHED_MASK) !=
+          CU_CTX_SCHED_BLOCKING_SYNC)
+        DP("Warning the current flags are not CU_CTX_SCHED_BLOCKING_SYNC\n");
+    } else {
+      DP("The primary context is inactive, set its flags to "
+         "CU_CTX_SCHED_BLOCKING_SYNC\n");
+      Err = cuDevicePrimaryCtxSetFlags(Device, CU_CTX_SCHED_BLOCKING_SYNC);
+      if (!checkResult(Err, "Error returned from cuDevicePrimaryCtxSetFlags\n"))
+        return OFFLOAD_FAIL;
+    }
+
+    // Retain the per device primary context and save it to use whenever this
+    // device is selected.
+    Err = cuDevicePrimaryCtxRetain(&DeviceData[DeviceId].Context, Device);
+    if (!checkResult(Err, "Error returned from cuDevicePrimaryCtxRetain\n"))
       return OFFLOAD_FAIL;
 
     Err = cuCtxSetCurrent(DeviceData[DeviceId].Context);


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