2.12.7-1

Add network communication through another GPU connected with NVLink
(PXN).
Add aggregation of messages coming from different local GPUs through
PXN and going to the same destination.
Add new v5 plugin API with grouped receives and tags.
Add compat for v4 plugins.
Add naming of NCCL threads to help debugging.
Fix NVLink detection and avoid data corruption when some NVLinks are
down.
Add support for Relaxed Ordering for IB.
Add profiling and timing infrastructure.

src/misc/shmutils.cc

@@ -0,0 +1,90 @@
+/*************************************************************************
+ * Copyright (c) 2016-2022, NVIDIA CORPORATION. All rights reserved.
+ *
+ * See LICENSE.txt for license information
+ ************************************************************************/
+
+#include "shm.h"
+#include "checks.h"
+#include <sys/types.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+// Change functions behavior to match other SYS functions
+static int shm_allocate(int fd, const int shmSize) {
+  int err = posix_fallocate(fd, 0, shmSize);
+  if (err) { errno = err; return -1; }
+  return 0;
+}
+static int shm_map(int fd, const int shmSize, void** ptr) {
+  *ptr = mmap(NULL, shmSize, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
+  return (*ptr == MAP_FAILED) ? -1 : 0;
+}
+
+static ncclResult_t ncclShmSetup(char* shmPath, const int shmSize, int* fd, void** ptr, int create) {
+  if (create) {
+    if (shmPath[0] == '\0') {
+      sprintf(shmPath, "/dev/shm/nccl-XXXXXX");
+      *fd = mkstemp(shmPath);
+    } else {
+      SYSCHECKVAL(open(shmPath, O_CREAT | O_RDWR, S_IRUSR | S_IWUSR), "open", *fd);
+    }
+    if (ftruncate(*fd, shmSize) != 0) {
+      WARN("Error: failed to extend %s to %d bytes", shmPath, shmSize);
+      return ncclSystemError;
+    }
+  } else {
+    SYSCHECKVAL(open(shmPath, O_RDWR, S_IRUSR | S_IWUSR), "open", *fd);
+  }
+  *ptr = (char*)mmap(NULL, shmSize, PROT_READ|PROT_WRITE, MAP_SHARED, *fd, 0);
+  if (*ptr == NULL) {
+    WARN("Could not map %s\n", shmPath);
+    return ncclSystemError;
+  }
+  close(*fd);
+  *fd = -1;
+  if (create) memset(*ptr, 0, shmSize);
+  return ncclSuccess;
+}
+
+ncclResult_t ncclShmOpen(char* shmPath, const int shmSize, void** shmPtr, void** devShmPtr, int create) {
+  int fd = -1;
+  void* ptr = MAP_FAILED;
+  ncclResult_t res = ncclSuccess;
+
+  NCCLCHECKGOTO(ncclShmSetup(shmPath, shmSize, &fd, &ptr, create), res, sysError);
+  if (devShmPtr) {
+    CUDACHECKGOTO(cudaHostRegister(ptr, shmSize, cudaHostRegisterMapped), res, cudaError);
+    CUDACHECKGOTO(cudaHostGetDevicePointer(devShmPtr, ptr, 0), res, cudaError);
+  }
+
+  *shmPtr = ptr;
+  return ncclSuccess;
+sysError:
+  WARN("Error while %s shared memory segment %s (size %d)", create ? "creating" : "attaching to", shmPath, shmSize);
+cudaError:
+  if (fd != -1) close(fd);
+  if (create) shm_unlink(shmPath);
+  if (ptr != MAP_FAILED) munmap(ptr, shmSize);
+  *shmPtr = NULL;
+  return res;
+}
+
+ncclResult_t ncclShmUnlink(const char* shmPath) {
+  if (shmPath != NULL) SYSCHECK(unlink(shmPath), "unlink");
+  return ncclSuccess;
+}
+
+ncclResult_t ncclShmClose(void* shmPtr, void* devShmPtr, const int shmSize) {
+  if (devShmPtr) CUDACHECK(cudaHostUnregister(shmPtr));
+  if (munmap(shmPtr, shmSize) != 0) {
+    WARN("munmap of shared memory failed");
+    return ncclSystemError;
+  }
+  return ncclSuccess;
+}