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/*
* Copyright © 2010-2016 Inria. All rights reserved.
* Copyright © 2010-2011 Université Bordeaux
* 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/helper.h>
#ifdef HWLOC_LINUX_SYS
#include <hwloc/linux.h>
#endif
#include <cuda.h>
#ifdef __cplusplus
extern "C" {
#endif
/** \defgroup hwlocality_cuda Interoperability with the CUDA Driver API
*
* This interface offers ways to retrieve topology information about
* CUDA devices when using the CUDA Driver API.
*
* @{
*/
/** \brief Return the domain, bus and device IDs of the CUDA device \p cudevice.
*
* Device \p cudevice must match the local machine.
*/
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.
*
* Return the CPU set describing the locality of the CUDA device \p cudevice.
*
* Topology \p topology and device \p cudevice must match the local machine.
* I/O devices detection and the CUDA component are not needed in the topology.
*
* The function only returns the locality of the device.
* If more information about the device is needed, OS objects should
* be used instead, see hwloc_cuda_get_device_osdev()
* and hwloc_cuda_get_device_osdev_by_index().
*
* This function is currently only implemented in a meaningful way for
* Linux; other systems will simply get a full cpuset.
*/
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;
if (!hwloc_topology_is_thissystem(topology)) {
errno = EINVAL;
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;
if (hwloc_linux_parse_cpumap_file(sysfile, set) < 0
|| 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 PCI device object corresponding to the
* CUDA device \p cudevice.
*
* Return the PCI device object describing the CUDA device \p cudevice.
* Return NULL if there is none.
*
* Topology \p topology and device \p cudevice must match the local machine.
* I/O devices detection must be enabled in topology \p topology.
* The CUDA component is not needed in the 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);
}
/** \brief Get the hwloc OS device object corresponding to CUDA device \p cudevice.
*
* Return the hwloc OS device object that describes the given
* CUDA device \p cudevice. Return NULL if there is none.
*
* Topology \p topology and device \p cudevice must match the local machine.
* I/O devices detection and the NVML component must be enabled in the topology.
* If not, the locality of the object may still be found using
* hwloc_cuda_get_device_cpuset().
*
* \note The corresponding hwloc PCI device may be found by looking
* at the result parent pointer.
*/
static __hwloc_inline hwloc_obj_t
hwloc_cuda_get_device_osdev(hwloc_topology_t topology, CUdevice cudevice)
{
hwloc_obj_t osdev = NULL;
int domain, bus, dev;
if (hwloc_cuda_get_device_pci_ids(topology, cudevice, &domain, &bus, &dev))
return NULL;
osdev = NULL;
while ((osdev = hwloc_get_next_osdev(topology, osdev)) != NULL) {
hwloc_obj_t pcidev = osdev->parent;
if (strncmp(osdev->name, "cuda", 4))
continue;
if (pcidev
&& pcidev->type == HWLOC_OBJ_PCI_DEVICE
&& (int) pcidev->attr->pcidev.domain == domain
&& (int) pcidev->attr->pcidev.bus == bus
&& (int) pcidev->attr->pcidev.dev == dev
&& pcidev->attr->pcidev.func == 0)
return osdev;
}
return NULL;
}
/** \brief Get the hwloc OS device object corresponding to the
* CUDA device whose index is \p idx.
*
* Return the OS device object describing the CUDA device whose
* index is \p idx. Return NULL if there is none.
*
* The topology \p topology does not necessarily have to match the current
* machine. For instance the topology may be an XML import of a remote host.
* I/O devices detection and the CUDA component must be enabled in the topology.
*
* \note The corresponding PCI device object can be obtained by looking
* at the OS device parent object.
*
* \note This function is identical to hwloc_cudart_get_device_osdev_by_index().
*/
static __hwloc_inline hwloc_obj_t
hwloc_cuda_get_device_osdev_by_index(hwloc_topology_t topology, unsigned idx)
{
hwloc_obj_t osdev = NULL;
while ((osdev = hwloc_get_next_osdev(topology, osdev)) != NULL) {
if (HWLOC_OBJ_OSDEV_COPROC == osdev->attr->osdev.type
&& osdev->name
&& !strncmp("cuda", osdev->name, 4)
&& atoi(osdev->name + 4) == (int) idx)
return osdev;
}
return NULL;
}
/** @} */
#ifdef __cplusplus
} /* extern "C" */
#endif
#endif /* HWLOC_CUDA_H */
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