OpenMPI  0.1.1
cudart.h
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1 /*
2  * Copyright © 2010 inria. All rights reserved.
3  * Copyright © 2010 Université Bordeaux 1
4  * Copyright © 2011 Cisco Systems, Inc. All rights reserved.
5  * See COPYING in top-level directory.
6  */
7 
8 /** \file
9  * \brief Macros to help interaction between hwloc and the CUDA Runtime API.
10  *
11  * Applications that use both hwloc and the CUDA Runtime API may want to
12  * include this file so as to get topology information for CUDA devices.
13  *
14  */
15 
16 #ifndef HWLOC_CUDART_H
17 #define HWLOC_CUDART_H
18 
19 #include <hwloc.h>
20 #include <hwloc/autogen/config.h>
21 #include <hwloc/linux.h>
22 
23 #include <cuda_runtime_api.h>
24 
25 
26 #ifdef __cplusplus
27 extern "C" {
28 #endif
29 
30 
31 /** \defgroup hwlocality_cudart CUDA Runtime API Specific Functions
32  * @{
33  */
34 
35 /** \brief Get the CPU set of logical processors that are physically
36  * close to device \p cudevice.
37  *
38  * For the given CUDA Runtime API device \p cudevice, read the corresponding
39  * kernel-provided cpumap file and return the corresponding CPU set.
40  * This function is currently only implemented in a meaningful way for
41  * Linux; other systems will simply get a full cpuset.
42  */
43 static __hwloc_inline int
44 hwloc_cudart_get_device_cpuset(hwloc_topology_t topology __hwloc_attribute_unused,
45  int device, hwloc_cpuset_t set)
46 {
47 #ifdef HWLOC_LINUX_SYS
48  /* If we're on Linux, use the sysfs mechanism to get the local cpus */
49 #define HWLOC_CUDART_DEVICE_SYSFS_PATH_MAX 128
50  cudaError_t cerr;
51  struct cudaDeviceProp prop;
52  char path[HWLOC_CUDART_DEVICE_SYSFS_PATH_MAX];
53  FILE *sysfile = NULL;
54  int pciDomainID = 0;
55 
56  cerr = cudaGetDeviceProperties(&prop, device);
57  if (cerr) {
58  errno = ENOSYS;
59  return -1;
60  }
61 
62 #if CUDART_VERSION >= 4000
63  pciDomainID = prop.pciDomainID;
64 #endif
65 
66  sprintf(path, "/sys/bus/pci/devices/%04x:%02x:%02x.0/local_cpus", pciDomainID, prop.pciBusID, prop.pciDeviceID);
67  sysfile = fopen(path, "r");
68  if (!sysfile)
69  return -1;
70 
71  hwloc_linux_parse_cpumap_file(sysfile, set);
72 
73  fclose(sysfile);
74 #else
75  /* Non-Linux systems simply get a full cpuset */
77 #endif
78  return 0;
79 }
80 
81 /** @} */
82 
83 
84 #ifdef __cplusplus
85 } /* extern "C" */
86 #endif
87 
88 
89 #endif /* HWLOC_CUDART_H */
HWLOC_DECLSPEC void hwloc_bitmap_copy(hwloc_bitmap_t dst, hwloc_const_bitmap_t src)
Copy the contents of bitmap src into the already allocated bitmap dst.
static __hwloc_inline int hwloc_cudart_get_device_cpuset(hwloc_topology_t topology __hwloc_attribute_unused, int device, hwloc_cpuset_t set)
Get the CPU set of logical processors that are physically close to device cudevice.
Definition: cudart.h:44
static __hwloc_inline hwloc_const_cpuset_t __hwloc_attribute_pure hwloc_topology_get_complete_cpuset(hwloc_topology_t topology)
Get complete CPU set.
Definition: helper.h:729
Macros to help interaction between hwloc and Linux.
HWLOC_DECLSPEC int hwloc_linux_parse_cpumap_file(FILE *file, hwloc_cpuset_t set)
Convert a linux kernel cpumap file file into hwloc CPU set.
Definition: topology-linux.c:1332
Definition: private.h:56
Definition: cpuset.c:38