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2012-07-03 12:55:31 +00:00

136 строки
3.6 KiB
C

/*
* Copyright © 2010-2012 inria. All rights reserved.
* Copyright © 2010-2011 Université Bordeaux 1
* Copyright © 2011 Cisco Systems, Inc. All rights reserved.
* See COPYING in top-level directory.
*/
/** \file
* \brief Macros to help interaction between hwloc and the CUDA Driver API.
*
* Applications that use both hwloc and the CUDA Driver API may want to
* include this file so as to get topology information for CUDA devices.
*
*/
#ifndef HWLOC_CUDA_H
#define HWLOC_CUDA_H
#include <hwloc.h>
#include <hwloc/autogen/config.h>
#include <hwloc/linux.h>
#include <hwloc/helper.h>
#include <cuda.h>
#ifdef __cplusplus
extern "C" {
#endif
/** \defgroup hwlocality_cuda CUDA Driver API Specific Functions
* @{
*/
/** \brief Return the domain, bus and device IDs of device \p cudevice.
*/
static __hwloc_inline int
hwloc_cuda_get_device_pci_ids(hwloc_topology_t topology __hwloc_attribute_unused,
CUdevice cudevice, int *domain, int *bus, int *dev)
{
CUresult cres;
#if CUDA_VERSION >= 4000
cres = cuDeviceGetAttribute(domain, CU_DEVICE_ATTRIBUTE_PCI_DOMAIN_ID, cudevice);
if (cres != CUDA_SUCCESS) {
errno = ENOSYS;
return -1;
}
#else
*domain = 0;
#endif
cres = cuDeviceGetAttribute(bus, CU_DEVICE_ATTRIBUTE_PCI_BUS_ID, cudevice);
if (cres != CUDA_SUCCESS) {
errno = ENOSYS;
return -1;
}
cres = cuDeviceGetAttribute(dev, CU_DEVICE_ATTRIBUTE_PCI_DEVICE_ID, cudevice);
if (cres != CUDA_SUCCESS) {
errno = ENOSYS;
return -1;
}
return 0;
}
/** \brief Get the CPU set of logical processors that are physically
* close to device \p cudevice.
*
* For the given CUDA Driver API device \p cudevice, read the corresponding
* kernel-provided cpumap file and return the corresponding CPU set.
* This function is currently only implemented in a meaningful way for
* Linux; other systems will simply get a full cpuset.
*
* Topology \p topology must match the current machine.
*/
static __hwloc_inline int
hwloc_cuda_get_device_cpuset(hwloc_topology_t topology __hwloc_attribute_unused,
CUdevice cudevice, hwloc_cpuset_t set)
{
#ifdef HWLOC_LINUX_SYS
/* If we're on Linux, use the sysfs mechanism to get the local cpus */
#define HWLOC_CUDA_DEVICE_SYSFS_PATH_MAX 128
char path[HWLOC_CUDA_DEVICE_SYSFS_PATH_MAX];
FILE *sysfile = NULL;
int domainid, busid, deviceid;
if (hwloc_cuda_get_device_pci_ids(topology, cudevice, &domainid, &busid, &deviceid))
return -1;
sprintf(path, "/sys/bus/pci/devices/%04x:%02x:%02x.0/local_cpus", domainid, busid, deviceid);
sysfile = fopen(path, "r");
if (!sysfile)
return -1;
hwloc_linux_parse_cpumap_file(sysfile, set);
if (hwloc_bitmap_iszero(set))
hwloc_bitmap_copy(set, hwloc_topology_get_complete_cpuset(topology));
fclose(sysfile);
#else
/* Non-Linux systems simply get a full cpuset */
hwloc_bitmap_copy(set, hwloc_topology_get_complete_cpuset(topology));
#endif
return 0;
}
/** \brief Get the hwloc object for the PCI device corresponding
* to device \p cudevice.
*
* For the given CUDA Runtime API device \p cudevice, return the hwloc PCI
* object containing the device. Returns NULL if there is none.
*
* IO devices detection must be enabled in topology \p topology.
*/
static __hwloc_inline hwloc_obj_t
hwloc_cuda_get_device_pcidev(hwloc_topology_t topology, CUdevice cudevice)
{
int domain, bus, dev;
if (hwloc_cuda_get_device_pci_ids(topology, cudevice, &domain, &bus, &dev))
return NULL;
return hwloc_get_pcidev_by_busid(topology, domain, bus, dev, 0);
}
/** @} */
#ifdef __cplusplus
} /* extern "C" */
#endif
#endif /* HWLOC_CUDA_H */