Adding a check to respect DMABUF being disabled by the user (#2076)

Co-authored-by: Marzieh Berenjkoub <mberenjk@.amd.com>

[ROCm/rccl commit: 9a443f3054]

projects/rccl/src/include/net.h

@@ -30,6 +30,7 @@ extern ncclNet_t ncclNetIb;
 extern ncclNet_t ncclNetSocket;
 
 extern ncclResult_t rcclNetP2pPolicy(void* handle, int isP2p);
+extern int64_t ncclParamDmaBufEnable();
 
 #if defined(__HIP_PLATFORM_AMD__) || defined(__HIPCC__)
 extern ncclNet_t rocmNetIb;

projects/rccl/src/transport/net_ib.cc

@@ -1990,7 +1990,7 @@ ib_recv:
     }
   }
 
-  useDmaBuf  = (ncclIbDmaBufSupport(lComm->dev) == ncclSuccess);
+  useDmaBuf  = (ncclIbDmaBufSupport(lComm->dev) == ncclSuccess && ncclParamDmaBufEnable());
   rComm->flushEnabled = ((ncclIbGdrSupport() == ncclSuccess || useDmaBuf)
                             && (ncclParamIbGdrFlushDisable() == 0)) ? 1 : 0;              
   for (int i = 0; i < rComm->base.vProps.ndevs; i++) {