X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Fnproc.c;h=1403f670f2ade5c9f92ae19f069622b7dd333584;hb=e7086a9a301ffcfef17edbcba9e7c0312c33f7a8;hp=7c9be94ae0e26e04ebd8cc7985fe39e2434e34b4;hpb=4e4fd5b6c34d828725994b7f444e18fcf3f85589;p=gnulib.git
diff --git a/lib/nproc.c b/lib/nproc.c
index 7c9be94ae..1403f670f 100644
--- a/lib/nproc.c
+++ b/lib/nproc.c
@@ -1,6 +1,6 @@
/* Detect the number of processors.
- Copyright (C) 2009 Free Software Foundation, Inc.
+ Copyright (C) 2009-2013 Free Software Foundation, Inc.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
@@ -13,8 +13,7 @@
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
- along with this program; if not, write to the Free Software Foundation,
- Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
+ along with this program; if not, see . */
/* Written by Glen Lenker and Bruno Haible. */
@@ -24,7 +23,7 @@
#include
#include
-#if HAVE_PTHREAD_AFFINITY_NP && 0
+#if HAVE_PTHREAD_GETAFFINITY_NP && 0
# include
# include
#endif
@@ -59,188 +58,236 @@
#define ARRAY_SIZE(a) (sizeof (a) / sizeof ((a)[0]))
-unsigned long int
-num_processors (enum nproc_query query)
+/* Return the number of processors available to the current process, based
+ on a modern system call that returns the "affinity" between the current
+ process and each CPU. Return 0 if unknown or if such a system call does
+ not exist. */
+static unsigned long
+num_processors_via_affinity_mask (void)
{
- if (query == NPROC_CURRENT_OVERRIDABLE)
- {
- /* Test the environment variable OMP_NUM_THREADS, recognized also by all
- programs that are based on OpenMP. The OpenMP spec says that the
- value assigned to the environment variable "may have leading and
- trailing white space". */
- const char *envvalue = getenv ("OMP_NUM_THREADS");
-
- if (envvalue != NULL)
- {
- while (*envvalue != '\0' && c_isspace (*envvalue))
- envvalue++;
- /* Convert it from decimal to 'unsigned long'. */
- if (c_isdigit (*envvalue))
- {
- char *endptr = NULL;
- unsigned long int value = strtoul (envvalue, &endptr, 10);
-
- if (endptr != NULL)
- {
- while (*endptr != '\0' && c_isspace (*endptr))
- endptr++;
- if (*endptr == '\0')
- return (value > 0 ? value : 1);
- }
- }
- }
-
- query = NPROC_CURRENT;
- }
- /* Here query is one of NPROC_ALL, NPROC_CURRENT. */
-
- if (query == NPROC_CURRENT)
- {
- /* glibc >= 2.3.3 with NPTL and NetBSD 5 have pthread_getaffinity_np,
- but with different APIs. Also it requires linking with -lpthread.
- Therefore this code is not enabled.
- glibc >= 2.3.4 has sched_getaffinity whereas NetBSD 5 has
- sched_getaffinity_np. */
-#if HAVE_PTHREAD_AFFINITY_NP && defined __GLIBC__ && 0
+ /* glibc >= 2.3.3 with NPTL and NetBSD 5 have pthread_getaffinity_np,
+ but with different APIs. Also it requires linking with -lpthread.
+ Therefore this code is not enabled.
+ glibc >= 2.3.4 has sched_getaffinity whereas NetBSD 5 has
+ sched_getaffinity_np. */
+#if HAVE_PTHREAD_GETAFFINITY_NP && defined __GLIBC__ && 0
+ {
+ cpu_set_t set;
+
+ if (pthread_getaffinity_np (pthread_self (), sizeof (set), &set) == 0)
{
- cpu_set_t set;
-
- if (pthread_getaffinity_np (pthread_self (), sizeof (set), &set) == 0)
- {
- unsigned long count;
+ unsigned long count;
# ifdef CPU_COUNT
- /* glibc >= 2.6 has the CPU_COUNT macro. */
- count = CPU_COUNT (&set);
+ /* glibc >= 2.6 has the CPU_COUNT macro. */
+ count = CPU_COUNT (&set);
# else
- size_t i;
+ size_t i;
- count = 0;
- for (i = 0; i < CPU_SETSIZE; i++)
- if (CPU_ISSET (i, &set))
- count++;
+ count = 0;
+ for (i = 0; i < CPU_SETSIZE; i++)
+ if (CPU_ISSET (i, &set))
+ count++;
# endif
- if (count > 0)
- return count;
- }
+ if (count > 0)
+ return count;
}
-#elif HAVE_PTHREAD_AFFINITY_NP && defined __NetBSD__ && 0
+ }
+#elif HAVE_PTHREAD_GETAFFINITY_NP && defined __NetBSD__ && 0
+ {
+ cpuset_t *set;
+
+ set = cpuset_create ();
+ if (set != NULL)
{
- cpuset_t *set;
-
- set = cpuset_create ();
- if (set != NULL)
- {
- unsigned long count = 0;
-
- if (pthread_getaffinity_np (pthread_self (), cpuset_size (set), set)
- == 0)
- {
- cpuid_t i;
-
- for (i = 0;; i++)
- {
- int ret = cpuset_isset (i, set);
- if (ret < 0)
- break;
- if (ret > 0)
- count++;
- }
- }
- cpuset_destroy (set);
- if (count > 0)
- return count;
- }
+ unsigned long count = 0;
+
+ if (pthread_getaffinity_np (pthread_self (), cpuset_size (set), set)
+ == 0)
+ {
+ cpuid_t i;
+
+ for (i = 0;; i++)
+ {
+ int ret = cpuset_isset (i, set);
+ if (ret < 0)
+ break;
+ if (ret > 0)
+ count++;
+ }
+ }
+ cpuset_destroy (set);
+ if (count > 0)
+ return count;
}
+ }
#elif HAVE_SCHED_GETAFFINITY_LIKE_GLIBC /* glibc >= 2.3.4 */
- {
- cpu_set_t set;
+ {
+ cpu_set_t set;
- if (sched_getaffinity (0, sizeof (set), &set) == 0)
- {
- unsigned long count;
+ if (sched_getaffinity (0, sizeof (set), &set) == 0)
+ {
+ unsigned long count;
# ifdef CPU_COUNT
- /* glibc >= 2.6 has the CPU_COUNT macro. */
- count = CPU_COUNT (&set);
+ /* glibc >= 2.6 has the CPU_COUNT macro. */
+ count = CPU_COUNT (&set);
# else
- size_t i;
+ size_t i;
- count = 0;
- for (i = 0; i < CPU_SETSIZE; i++)
- if (CPU_ISSET (i, &set))
- count++;
+ count = 0;
+ for (i = 0; i < CPU_SETSIZE; i++)
+ if (CPU_ISSET (i, &set))
+ count++;
# endif
- if (count > 0)
- return count;
- }
+ if (count > 0)
+ return count;
}
+ }
#elif HAVE_SCHED_GETAFFINITY_NP /* NetBSD >= 5 */
+ {
+ cpuset_t *set;
+
+ set = cpuset_create ();
+ if (set != NULL)
{
- cpuset_t *set;
-
- set = cpuset_create ();
- if (set != NULL)
- {
- unsigned long count = 0;
-
- if (sched_getaffinity_np (getpid (), cpuset_size (set), set) == 0)
- {
- cpuid_t i;
-
- for (i = 0;; i++)
- {
- int ret = cpuset_isset (i, set);
- if (ret < 0)
- break;
- if (ret > 0)
- count++;
- }
- }
- cpuset_destroy (set);
- if (count > 0)
- return count;
- }
+ unsigned long count = 0;
+
+ if (sched_getaffinity_np (getpid (), cpuset_size (set), set) == 0)
+ {
+ cpuid_t i;
+
+ for (i = 0;; i++)
+ {
+ int ret = cpuset_isset (i, set);
+ if (ret < 0)
+ break;
+ if (ret > 0)
+ count++;
+ }
+ }
+ cpuset_destroy (set);
+ if (count > 0)
+ return count;
}
+ }
#endif
#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
- { /* This works on native Windows platforms. */
- DWORD_PTR process_mask;
- DWORD_PTR system_mask;
-
- if (GetProcessAffinityMask (GetCurrentProcess (),
- &process_mask, &system_mask))
- {
- DWORD_PTR mask = process_mask;
- unsigned long count = 0;
-
- for (; mask != 0; mask = mask >> 1)
- if (mask & 1)
- count++;
- if (count > 0)
- return count;
- }
+ { /* This works on native Windows platforms. */
+ DWORD_PTR process_mask;
+ DWORD_PTR system_mask;
+
+ if (GetProcessAffinityMask (GetCurrentProcess (),
+ &process_mask, &system_mask))
+ {
+ DWORD_PTR mask = process_mask;
+ unsigned long count = 0;
+
+ for (; mask != 0; mask = mask >> 1)
+ if (mask & 1)
+ count++;
+ if (count > 0)
+ return count;
}
+ }
#endif
+ return 0;
+}
+
+unsigned long int
+num_processors (enum nproc_query query)
+{
+ if (query == NPROC_CURRENT_OVERRIDABLE)
+ {
+ /* Test the environment variable OMP_NUM_THREADS, recognized also by all
+ programs that are based on OpenMP. The OpenMP spec says that the
+ value assigned to the environment variable "may have leading and
+ trailing white space". */
+ const char *envvalue = getenv ("OMP_NUM_THREADS");
+
+ if (envvalue != NULL)
+ {
+ while (*envvalue != '\0' && c_isspace (*envvalue))
+ envvalue++;
+ /* Convert it from decimal to 'unsigned long'. */
+ if (c_isdigit (*envvalue))
+ {
+ char *endptr = NULL;
+ unsigned long int value = strtoul (envvalue, &endptr, 10);
+
+ if (endptr != NULL)
+ {
+ while (*endptr != '\0' && c_isspace (*endptr))
+ endptr++;
+ if (*endptr == '\0')
+ return (value > 0 ? value : 1);
+ }
+ }
+ }
+
+ query = NPROC_CURRENT;
+ }
+ /* Here query is one of NPROC_ALL, NPROC_CURRENT. */
+
+ /* On systems with a modern affinity mask system call, we have
+ sysconf (_SC_NPROCESSORS_CONF)
+ >= sysconf (_SC_NPROCESSORS_ONLN)
+ >= num_processors_via_affinity_mask ()
+ The first number is the number of CPUs configured in the system.
+ The second number is the number of CPUs available to the scheduler.
+ The third number is the number of CPUs available to the current process.
+
+ Note! On Linux systems with glibc, the first and second number come from
+ the /sys and /proc file systems (see
+ glibc/sysdeps/unix/sysv/linux/getsysstats.c).
+ In some situations these file systems are not mounted, and the sysconf
+ call returns 1, which does not reflect the reality. */
+
+ if (query == NPROC_CURRENT)
+ {
+ /* Try the modern affinity mask system call. */
+ {
+ unsigned long nprocs = num_processors_via_affinity_mask ();
+
+ if (nprocs > 0)
+ return nprocs;
+ }
+
#if defined _SC_NPROCESSORS_ONLN
- { /* This works on glibc, MacOS X 10.5, FreeBSD, AIX, OSF/1, Solaris,
- Cygwin, Haiku. */
- long int nprocs = sysconf (_SC_NPROCESSORS_ONLN);
- if (nprocs > 0)
- return nprocs;
+ { /* This works on glibc, Mac OS X 10.5, FreeBSD, AIX, OSF/1, Solaris,
+ Cygwin, Haiku. */
+ long int nprocs = sysconf (_SC_NPROCESSORS_ONLN);
+ if (nprocs > 0)
+ return nprocs;
}
#endif
}
else /* query == NPROC_ALL */
{
#if defined _SC_NPROCESSORS_CONF
- { /* This works on glibc, MacOS X 10.5, FreeBSD, AIX, OSF/1, Solaris,
- Cygwin, Haiku. */
- long int nprocs = sysconf (_SC_NPROCESSORS_CONF);
- if (nprocs > 0)
- return nprocs;
+ { /* This works on glibc, Mac OS X 10.5, FreeBSD, AIX, OSF/1, Solaris,
+ Cygwin, Haiku. */
+ long int nprocs = sysconf (_SC_NPROCESSORS_CONF);
+
+# if __GLIBC__ >= 2 && defined __linux__
+ /* On Linux systems with glibc, this information comes from the /sys and
+ /proc file systems (see glibc/sysdeps/unix/sysv/linux/getsysstats.c).
+ In some situations these file systems are not mounted, and the
+ sysconf call returns 1. But we wish to guarantee that
+ num_processors (NPROC_ALL) >= num_processors (NPROC_CURRENT). */
+ if (nprocs == 1)
+ {
+ unsigned long nprocs_current = num_processors_via_affinity_mask ();
+
+ if (nprocs_current > 0)
+ nprocs = nprocs_current;
+ }
+# endif
+
+ if (nprocs > 0)
+ return nprocs;
}
#endif
}
@@ -250,19 +297,19 @@ num_processors (enum nproc_query query)
struct pst_dynamic psd;
if (pstat_getdynamic (&psd, sizeof psd, 1, 0) >= 0)
{
- /* The field psd_proc_cnt contains the number of active processors.
- In newer releases of HP-UX 11, the field psd_max_proc_cnt includes
- deactivated processors. */
- if (query == NPROC_CURRENT)
- {
- if (psd.psd_proc_cnt > 0)
- return psd.psd_proc_cnt;
- }
- else
- {
- if (psd.psd_max_proc_cnt > 0)
- return psd.psd_max_proc_cnt;
- }
+ /* The field psd_proc_cnt contains the number of active processors.
+ In newer releases of HP-UX 11, the field psd_max_proc_cnt includes
+ deactivated processors. */
+ if (query == NPROC_CURRENT)
+ {
+ if (psd.psd_proc_cnt > 0)
+ return psd.psd_proc_cnt;
+ }
+ else
+ {
+ if (psd.psd_max_proc_cnt > 0)
+ return psd.psd_max_proc_cnt;
+ }
}
}
#endif
@@ -274,8 +321,8 @@ num_processors (enum nproc_query query)
processes. */
int nprocs =
sysmp (query == NPROC_CURRENT && getpid () != 0
- ? MP_NAPROCS
- : MP_NPROCS);
+ ? MP_NAPROCS
+ : MP_NPROCS);
if (nprocs > 0)
return nprocs;
}
@@ -285,14 +332,14 @@ num_processors (enum nproc_query query)
NPROC_CURRENT and NPROC_ALL. */
#if HAVE_SYSCTL && defined HW_NCPU
- { /* This works on MacOS X, FreeBSD, NetBSD, OpenBSD. */
+ { /* This works on Mac OS X, FreeBSD, NetBSD, OpenBSD. */
int nprocs;
size_t len = sizeof (nprocs);
static int mib[2] = { CTL_HW, HW_NCPU };
if (sysctl (mib, ARRAY_SIZE (mib), &nprocs, &len, NULL, 0) == 0
- && len == sizeof (nprocs)
- && 0 < nprocs)
+ && len == sizeof (nprocs)
+ && 0 < nprocs)
return nprocs;
}
#endif