Enable GDR copy by default

ROCm · Dec 17, 2024 · 40f7bd1 · 40f7bd1
1 parent 86bfa80
commit 40f7bd1
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Showing 2 changed files with 6 additions and 1 deletion.
diff --git a/src/init.cc b/src/init.cc
@@ -122,7 +122,7 @@ static constexpr int64_t defaultEnableMscclpp = 0;
 RCCL_PARAM(MscclppEnabled, "MSCCLPP_ENABLE", defaultEnableMscclpp);
 
 // GDRCOPY support: Off by default
-NCCL_PARAM(GdrCopyEnable, "GDRCOPY_ENABLE", 0);
+NCCL_PARAM(GdrCopyEnable, "GDRCOPY_ENABLE", 1);
 
 // GDRCOPY support
 gdr_t ncclGdrCopy = NULL;

diff --git a/src/transport/net.cc b/src/transport/net.cc
@@ -1558,7 +1558,12 @@ static ncclResult_t recvProxyProgress(struct ncclProxyState* proxyState, struct
             if (resources->gdcFlush) {
 #if defined (__x86_64__)
               // Force a PCI-E read from GPU memory
+              static bool once = true;
               asm volatile ("mov (%0), %%eax" :: "l"(resources->gdcFlush) : "%eax");
+              if (once) {
+                once = false;
+                INFO(NCCL_INIT, "%s: issued GDC flush", __func__);
+              }
 #else
               WARN("NET: GDR Flush only supported on x86_64");
               return ncclInternalError;