Disable direct buffers to reduce scratch memory size

src/collectives/device/primitives.h

@@ -47,8 +47,10 @@ class ncclPrimitives {
   uint64_t recvStep[NRECV];
   uint64_t sendStep[NSEND];
   uint64_t sendConnHead[NSEND];
+#if defined(RCCL_USE_DIRECT_BUFFER)
   const T* recvDirectBuff[NRECV];
   T* sendDirectBuff[NSEND];
+#endif
   const T* recvBuff[NRECV];
   T* sendBuff[NSEND];
   struct ncclDevComm* comm;
@@ -144,12 +146,20 @@ class ncclPrimitives {
 
   template <int DIRECTRECV>
   __device__ const T* directRecvPtr(int i, int directOffset) {
+#if defined(RCCL_USE_DIRECT_BUFFER)
     return DIRECTRECV && recvDirectBuff[i] ? recvDirectBuff[i]+directOffset : recvPtr(i);
+#else
+    return recvPtr(i);
+#endif
   }
 
   template <int DIRECTSEND>
   __device__ T* directSendPtr(int i, int directOffset) {
+  #if defined(RCCL_USE_DIRECT_BUFFER)
     return DIRECTSEND && sendDirectBuff[i] ? sendDirectBuff[i]+directOffset : sendPtr(i);
+  #else
+    return sendPtr(i);
+  #endif
   }
 
   template <int DIRECTRECV, int DIRECTSEND, int RECV, int SEND, int SRC, int DST>
@@ -179,6 +189,7 @@ class ncclPrimitives {
       FOR_RECV(waitRecv);
       if (realSize > 0) {
         barrier();
+#if defined(RCCL_USE_DIRECT_BUFFER)
         if (DIRECTRECV && recvDirectBuff[0]) {
           // We can only have one direct receive. Since srcs[0] == dstPtr+offset, skip one copy
           if (SEND) {
@@ -187,6 +198,9 @@ class ncclPrimitives {
         } else {
           ReduceOrCopyMulti<UNROLL, FUNC, T, RECV+SRC, RECV*NRECV+SRC, SEND+DST, SEND*NSEND+DST>(tid, nthreads, RECV*nrecv+SRC, srcs, SEND*nsend+DST, dsts, realSize);
         }
+#else
+        ReduceOrCopyMulti<UNROLL, FUNC, T, RECV+SRC, RECV*NRECV+SRC, SEND+DST, SEND*NSEND+DST>(tid, nthreads, RECV*nrecv+SRC, srcs, SEND*nsend+DST, dsts, realSize);
+#endif
       }
       exitIfAbortBarrier(abort, abortCount);
       if (tid == 0)
@@ -214,11 +228,13 @@ class ncclPrimitives {
       waitPtr = LOAD(&recvConn[i]->tail);
       STORE(recvConn[i]->opCountLoc, opCount);
     }
+#if defined(RCCL_USE_DIRECT_BUFFER)
     recvDirectBuff[i] = NULL;
     if (directBuff && recvConn[i]->direct) {
       recvDirectBuff[i] = directBuff;
       if (tid == 0) STORE(recvConn[i]->ptrExchange, directBuff);
     }
+#endif
     nrecv++;
   }
 
@@ -232,6 +248,7 @@ class ncclPrimitives {
       sendConnHead[i] = LOAD(waitPtr);
       STORE(sendConn[i]->opCountLoc, opCount);
     }
+#if defined(RCCL_USE_DIRECT_BUFFER)
     sendDirectBuff[i] = NULL;
     if (directBuff && sendConn[i]->direct) {
       void* volatile* ptr = sendConn[i]->ptrExchange;
@@ -239,6 +256,7 @@ class ncclPrimitives {
       __syncthreads();
       if (tid == 0) STORE(ptr, NULL);
     }
+#endif
     nsend++;
   }