On 10/10/21 5:21 AM, Stefan Kangas wrote:
Omar Polo <o...@omarpolo.com> writes:
OpenBSD disables hyperthreading by default so HW_NCPU is (almost) always
misleading. For example, on my machine
% uname -a
OpenBSD venera 7.0 GENERIC.MP#221 amd64
% sysctl hw.ncpu
hw.ncpu=8
% sysctl hw.ncpuonline
hw.ncpuonline=4
and this has been the case for a while already (I mean, a couple of
years if not more.)
BTW, Gnulib doesn't seem to make this distinction (lib/nproc.c:313).
Maybe that should be reported to the Gnulib developers?
No need for a bug report as I'm one of those developers. To fix the
Gnulib nproc OpenBSD issue I installed the first attached patch into
Gnulib, and to port Emacs's recently-added processor-count code to more
platforms I installed the second attached patch into Emacs's emacs-28
branch. Although I think the latter patch means that
emacs/src/w32proc.c's w32-get-nproc function can be removed, I'll let
the Emacs MS-Windows experts opine on that.
From 7fc3219bcc2bf448ef26cf30a2e5770fdda3f2b4 Mon Sep 17 00:00:00 2001
From: Paul Eggert <egg...@cs.ucla.edu>
Date: Sun, 10 Oct 2021 10:43:47 -0700
Subject: [PATCH] nproc: port better to OpenBSD
Problem reported by Omar Polo in:
https://lists.gnu.org/r/emacs-devel/2021-10/msg00692.html
* lib/nproc.c (num_processors_ignoring_omp): Prefer HW_NCPUONLINE
to HW_NCPU, for OpenBSD. Also, make mib const.
---
ChangeLog | 8 ++++++++
lib/nproc.c | 19 +++++++++++++------
2 files changed, 21 insertions(+), 6 deletions(-)
diff --git a/ChangeLog b/ChangeLog
index 232d2dec3..da5b570ee 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2021-10-10 Paul Eggert <egg...@cs.ucla.edu>
+
+ nproc: port better to OpenBSD
+ Problem reported by Omar Polo in:
+ https://lists.gnu.org/r/emacs-devel/2021-10/msg00692.html
+ * lib/nproc.c (num_processors_ignoring_omp): Prefer HW_NCPUONLINE
+ to HW_NCPU, for OpenBSD. Also, make mib const.
+
2021-10-02 Paul Eggert <egg...@cs.ucla.edu>
timer-time: port better to OpenBSD 6.9
diff --git a/lib/nproc.c b/lib/nproc.c
index e3ddb9288..a9e369dd3 100644
--- a/lib/nproc.c
+++ b/lib/nproc.c
@@ -310,12 +310,19 @@ num_processors_ignoring_omp (enum nproc_query query)
{ /* 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)
- return nprocs;
+ static int const mib[][2] = {
+# ifdef HW_NCPUONLINE
+ { CTL_HW, HW_NCPUONLINE },
+# endif
+ { CTL_HW, HW_NCPU }
+ };
+ for (int i = 0; i < ARRAY_SIZE (mib); i++)
+ {
+ if (sysctl (mib[i], ARRAY_SIZE (mib[i]), &nprocs, &len, NULL, 0) == 0
+ && len == sizeof (nprocs)
+ && 0 < nprocs)
+ return nprocs;
+ }
}
#endif
--
2.30.2
From 96278de8ac2166c37925f2dfbc0eeb6d368142b9 Mon Sep 17 00:00:00 2001
From: Paul Eggert <egg...@cs.ucla.edu>
Date: Sun, 10 Oct 2021 13:59:16 -0700
Subject: [PATCH] New function num-processors
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
This addresses a FIXME comment in lisp/emacs-lisp/comp.el,
relating to the number of subsidiary processes used by
comp-run-async-workers in native compilation.
* admin/merge-gnulib (GNULIB_MODULES): Add nproc.
* doc/lispref/processes.texi (Process Information), etc/NEWS:
Document num-processors.
* lib/gnulib.mk.in, m4/gnulib-comp.m4: Regenerate.
* lib/nproc.c, lib/nproc.h, m4/nproc.m4:
New files, copied from Gnulib by admin/merge-gnulib.
* lisp/emacs-lisp/comp.el (w32-get-nproc): Remove decl.
(comp-effective-async-max-jobs): Use num-processors.
* src/process.c: Include nproc.h.
(Fnum_processors): New function.
(syms_of_process): Define ‘all’, ‘current’, ‘num-processors’.
* src/w32proc.c (Fw32_get_nproc): Add FIXME comment.
* test/src/process-tests.el (process-num-processors): New test.
---
admin/merge-gnulib | 3 +-
doc/lispref/processes.texi | 13 ++
etc/NEWS | 4 +
lib/gnulib.mk.in | 11 +
lib/nproc.c | 403 +++++++++++++++++++++++++++++++++++++
lib/nproc.h | 46 +++++
lisp/emacs-lisp/comp.el | 15 +-
m4/gnulib-comp.m4 | 5 +
m4/nproc.m4 | 54 +++++
src/process.c | 18 ++
src/w32proc.c | 1 +
test/src/process-tests.el | 6 +
12 files changed, 564 insertions(+), 15 deletions(-)
create mode 100644 lib/nproc.c
create mode 100644 lib/nproc.h
create mode 100644 m4/nproc.m4
diff --git a/admin/merge-gnulib b/admin/merge-gnulib
index 886f37e28c..c9fe3b2f95 100755
--- a/admin/merge-gnulib
+++ b/admin/merge-gnulib
@@ -39,7 +39,8 @@ GNULIB_MODULES=
free-posix fstatat fsusage fsync futimens
getloadavg getopt-gnu getrandom gettime gettimeofday gitlog-to-changelog
ieee754-h ignore-value intprops largefile libgmp lstat
- manywarnings memmem-simple mempcpy memrchr minmax mkostemp mktime nstrftime
+ manywarnings memmem-simple mempcpy memrchr minmax mkostemp mktime
+ nproc nstrftime
pathmax pipe2 pselect pthread_sigmask
qcopy-acl readlink readlinkat regex
sig2str sigdescr_np socklen stat-time std-gnu11 stdalign stddef stdio
diff --git a/doc/lispref/processes.texi b/doc/lispref/processes.texi
index 90c4215637..d90097d0b0 100644
--- a/doc/lispref/processes.texi
+++ b/doc/lispref/processes.texi
@@ -1047,6 +1047,19 @@ Process Information
@end smallexample
@end defun
+@defun num-processors &optional query
+This function returns the number of processors, a positive integer.
+Each usable thread execution unit counts as a processor.
+By default, the count includes the number of available processors,
+which you can override by setting the
+@url{https://www.openmp.org/spec-html/5.1/openmpse59.html,
+@env{OMP_NUM_THREADS} environment variable of OpenMP}.
+If the optional argument @var{query} is @code{current},
+this function ignores @env{OMP_NUM_THREADS};
+if @var{query} is @code{all}, this function also counts processors
+that are on the system but are not available to the current process.
+@end defun
+
@defun get-process name
This function returns the process named @var{name} (a string), or
@code{nil} if there is none. The argument @var{name} can also be a
diff --git a/etc/NEWS b/etc/NEWS
index 09537d7d31..791248f7dc 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -4094,6 +4094,10 @@ Parse a string as a mail address-like string.
** New function 'make-separator-line'.
Make a string appropriate for usage as a visual separator line.
++++
+** New function 'num-processors'.
+Return the number of processors on the system.
+
+++
** New function 'object-intervals'.
This function returns a copy of the list of intervals (i.e., text
diff --git a/lib/gnulib.mk.in b/lib/gnulib.mk.in
index e9a1a5dc02..c7c7eb455b 100644
--- a/lib/gnulib.mk.in
+++ b/lib/gnulib.mk.in
@@ -129,6 +129,7 @@
# minmax \
# mkostemp \
# mktime \
+# nproc \
# nstrftime \
# pathmax \
# pipe2 \
@@ -2378,6 +2379,16 @@ EXTRA_libgnu_a_SOURCES += mktime.c
endif
## end gnulib module mktime-internal
+## begin gnulib module nproc
+ifeq (,$(OMIT_GNULIB_MODULE_nproc))
+
+libgnu_a_SOURCES += nproc.c
+
+EXTRA_DIST += nproc.h
+
+endif
+## end gnulib module nproc
+
## begin gnulib module nstrftime
ifeq (,$(OMIT_GNULIB_MODULE_nstrftime))
diff --git a/lib/nproc.c b/lib/nproc.c
new file mode 100644
index 0000000000..a9e369dd3f
--- /dev/null
+++ b/lib/nproc.c
@@ -0,0 +1,403 @@
+/* Detect the number of processors.
+
+ Copyright (C) 2009-2021 Free Software Foundation, Inc.
+
+ This file is free software: you can redistribute it and/or modify
+ it under the terms of the GNU Lesser General Public License as
+ published by the Free Software Foundation; either version 2.1 of the
+ License, or (at your option) any later version.
+
+ This file is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public License
+ along with this program. If not, see <https://www.gnu.org/licenses/>. */
+
+/* Written by Glen Lenker and Bruno Haible. */
+
+#include <config.h>
+#include "nproc.h"
+
+#include <limits.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#if HAVE_PTHREAD_GETAFFINITY_NP && 0
+# include <pthread.h>
+# include <sched.h>
+#endif
+#if HAVE_SCHED_GETAFFINITY_LIKE_GLIBC || HAVE_SCHED_GETAFFINITY_NP
+# include <sched.h>
+#endif
+
+#include <sys/types.h>
+
+#if HAVE_SYS_PSTAT_H
+# include <sys/pstat.h>
+#endif
+
+#if HAVE_SYS_SYSMP_H
+# include <sys/sysmp.h>
+#endif
+
+#if HAVE_SYS_PARAM_H
+# include <sys/param.h>
+#endif
+
+#if HAVE_SYS_SYSCTL_H && ! defined __GLIBC__
+# include <sys/sysctl.h>
+#endif
+
+#if defined _WIN32 && ! defined __CYGWIN__
+# define WIN32_LEAN_AND_MEAN
+# include <windows.h>
+#endif
+
+#include "c-ctype.h"
+
+#include "minmax.h"
+
+#define ARRAY_SIZE(a) (sizeof (a) / sizeof ((a)[0]))
+
+/* 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)
+{
+ /* 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)
+ {
+ unsigned long count;
+
+# ifdef CPU_COUNT
+ /* glibc >= 2.6 has the CPU_COUNT macro. */
+ count = CPU_COUNT (&set);
+# else
+ size_t i;
+
+ count = 0;
+ for (i = 0; i < CPU_SETSIZE; i++)
+ if (CPU_ISSET (i, &set))
+ count++;
+# endif
+ if (count > 0)
+ return count;
+ }
+ }
+#elif HAVE_PTHREAD_GETAFFINITY_NP && defined __NetBSD__ && 0
+ {
+ 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;
+ }
+ }
+#elif HAVE_SCHED_GETAFFINITY_LIKE_GLIBC /* glibc >= 2.3.4 */
+ {
+ cpu_set_t set;
+
+ 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);
+# else
+ size_t i;
+
+ count = 0;
+ for (i = 0; i < CPU_SETSIZE; i++)
+ if (CPU_ISSET (i, &set))
+ count++;
+# endif
+ if (count > 0)
+ return count;
+ }
+ }
+#elif HAVE_SCHED_GETAFFINITY_NP /* NetBSD >= 5 */
+ {
+ 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;
+ }
+ }
+#endif
+
+#if 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;
+ }
+ }
+#endif
+
+ return 0;
+}
+
+
+/* Return the total number of processors. Here QUERY must be one of
+ NPROC_ALL, NPROC_CURRENT. The result is guaranteed to be at least 1. */
+static unsigned long int
+num_processors_ignoring_omp (enum nproc_query query)
+{
+ /* 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 or 2 (<https://sourceware.org/bugzilla/show_bug.cgi?id=21542>),
+ 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, 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, 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 or 2. But we wish to guarantee that
+ num_processors (NPROC_ALL) >= num_processors (NPROC_CURRENT). */
+ if (nprocs == 1 || nprocs == 2)
+ {
+ unsigned long nprocs_current = num_processors_via_affinity_mask ();
+
+ if (/* nprocs_current > 0 && */ nprocs_current > nprocs)
+ nprocs = nprocs_current;
+ }
+# endif
+
+ if (nprocs > 0)
+ return nprocs;
+ }
+#endif
+ }
+
+#if HAVE_PSTAT_GETDYNAMIC
+ { /* This works on HP-UX. */
+ 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;
+ }
+ }
+ }
+#endif
+
+#if HAVE_SYSMP && defined MP_NAPROCS && defined MP_NPROCS
+ { /* This works on IRIX. */
+ /* MP_NPROCS yields the number of installed processors.
+ MP_NAPROCS yields the number of processors available to unprivileged
+ processes. */
+ int nprocs =
+ sysmp (query == NPROC_CURRENT && getuid () != 0
+ ? MP_NAPROCS
+ : MP_NPROCS);
+ if (nprocs > 0)
+ return nprocs;
+ }
+#endif
+
+ /* Finally, as fallback, use the APIs that don't distinguish between
+ NPROC_CURRENT and NPROC_ALL. */
+
+#if HAVE_SYSCTL && ! defined __GLIBC__ && defined HW_NCPU
+ { /* This works on Mac OS X, FreeBSD, NetBSD, OpenBSD. */
+ int nprocs;
+ size_t len = sizeof (nprocs);
+ static int const mib[][2] = {
+# ifdef HW_NCPUONLINE
+ { CTL_HW, HW_NCPUONLINE },
+# endif
+ { CTL_HW, HW_NCPU }
+ };
+ for (int i = 0; i < ARRAY_SIZE (mib); i++)
+ {
+ if (sysctl (mib[i], ARRAY_SIZE (mib[i]), &nprocs, &len, NULL, 0) == 0
+ && len == sizeof (nprocs)
+ && 0 < nprocs)
+ return nprocs;
+ }
+ }
+#endif
+
+#if defined _WIN32 && ! defined __CYGWIN__
+ { /* This works on native Windows platforms. */
+ SYSTEM_INFO system_info;
+ GetSystemInfo (&system_info);
+ if (0 < system_info.dwNumberOfProcessors)
+ return system_info.dwNumberOfProcessors;
+ }
+#endif
+
+ return 1;
+}
+
+/* Parse OMP environment variables without dependence on OMP.
+ Return 0 for invalid values. */
+static unsigned long int
+parse_omp_threads (char const* threads)
+{
+ unsigned long int ret = 0;
+
+ if (threads == NULL)
+ return ret;
+
+ /* The OpenMP spec says that the value assigned to the environment variables
+ "may have leading and trailing white space". */
+ while (*threads != '\0' && c_isspace (*threads))
+ threads++;
+
+ /* Convert it from positive decimal to 'unsigned long'. */
+ if (c_isdigit (*threads))
+ {
+ char *endptr = NULL;
+ unsigned long int value = strtoul (threads, &endptr, 10);
+
+ if (endptr != NULL)
+ {
+ while (*endptr != '\0' && c_isspace (*endptr))
+ endptr++;
+ if (*endptr == '\0')
+ return value;
+ /* Also accept the first value in a nesting level,
+ since we can't determine the nesting level from env vars. */
+ else if (*endptr == ',')
+ return value;
+ }
+ }
+
+ return ret;
+}
+
+unsigned long int
+num_processors (enum nproc_query query)
+{
+ unsigned long int omp_env_limit = ULONG_MAX;
+
+ if (query == NPROC_CURRENT_OVERRIDABLE)
+ {
+ unsigned long int omp_env_threads;
+ /* Honor the OpenMP environment variables, recognized also by all
+ programs that are based on OpenMP. */
+ omp_env_threads = parse_omp_threads (getenv ("OMP_NUM_THREADS"));
+ omp_env_limit = parse_omp_threads (getenv ("OMP_THREAD_LIMIT"));
+ if (! omp_env_limit)
+ omp_env_limit = ULONG_MAX;
+
+ if (omp_env_threads)
+ return MIN (omp_env_threads, omp_env_limit);
+
+ query = NPROC_CURRENT;
+ }
+ /* Here query is one of NPROC_ALL, NPROC_CURRENT. */
+ {
+ unsigned long nprocs = num_processors_ignoring_omp (query);
+ return MIN (nprocs, omp_env_limit);
+ }
+}
diff --git a/lib/nproc.h b/lib/nproc.h
new file mode 100644
index 0000000000..d7659a5cad
--- /dev/null
+++ b/lib/nproc.h
@@ -0,0 +1,46 @@
+/* Detect the number of processors.
+
+ Copyright (C) 2009-2021 Free Software Foundation, Inc.
+
+ This file is free software: you can redistribute it and/or modify
+ it under the terms of the GNU Lesser General Public License as
+ published by the Free Software Foundation; either version 2.1 of the
+ License, or (at your option) any later version.
+
+ This file is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public License
+ along with this program. If not, see <https://www.gnu.org/licenses/>. */
+
+/* Written by Glen Lenker and Bruno Haible. */
+
+/* Allow the use in C++ code. */
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* A "processor" in this context means a thread execution unit, that is either
+ - an execution core in a (possibly multi-core) chip, in a (possibly multi-
+ chip) module, in a single computer, or
+ - a thread execution unit inside a core
+ (hyper-threading, see <https://en.wikipedia.org/wiki/Hyper-threading>).
+ Which of the two definitions is used, is unspecified. */
+
+enum nproc_query
+{
+ NPROC_ALL, /* total number of processors */
+ NPROC_CURRENT, /* processors available to the current process */
+ NPROC_CURRENT_OVERRIDABLE /* likewise, but overridable through the
+ OMP_NUM_THREADS environment variable */
+};
+
+/* Return the total number of processors. The result is guaranteed to
+ be at least 1. */
+extern unsigned long int num_processors (enum nproc_query query);
+
+#ifdef __cplusplus
+}
+#endif /* C++ */
diff --git a/lisp/emacs-lisp/comp.el b/lisp/emacs-lisp/comp.el
index 63d4a74b54..0052fd0f8d 100644
--- a/lisp/emacs-lisp/comp.el
+++ b/lisp/emacs-lisp/comp.el
@@ -3876,26 +3876,13 @@ comp-async-runnings
do (remhash file-name comp-async-compilations))
(hash-table-count comp-async-compilations))
-(declare-function w32-get-nproc "w32.c")
(defvar comp-num-cpus nil)
(defun comp-effective-async-max-jobs ()
"Compute the effective number of async jobs."
(if (zerop native-comp-async-jobs-number)
(or comp-num-cpus
(setf comp-num-cpus
- ;; FIXME: we already have a function to determine
- ;; the number of processors, see get_native_system_info in w32.c.
- ;; The result needs to be exported to Lisp.
- (max 1 (/ (cond ((eq 'windows-nt system-type)
- (w32-get-nproc))
- ((executable-find "nproc")
- (string-to-number
- (shell-command-to-string "nproc")))
- ((eq 'berkeley-unix system-type)
- (string-to-number
- (shell-command-to-string "sysctl -n hw.ncpu")))
- (t 1))
- 2))))
+ (max 1 (/ (num-processors) 2))))
native-comp-async-jobs-number))
(defvar comp-last-scanned-async-output nil)
diff --git a/m4/gnulib-comp.m4 b/m4/gnulib-comp.m4
index a795fe7651..e314edcfb5 100644
--- a/m4/gnulib-comp.m4
+++ b/m4/gnulib-comp.m4
@@ -139,6 +139,7 @@ AC_DEFUN
# Code from module mktime-internal:
# Code from module multiarch:
# Code from module nocrash:
+ # Code from module nproc:
# Code from module nstrftime:
# Code from module open:
# Code from module openat-h:
@@ -413,6 +414,7 @@ AC_DEFUN
fi
gl_TIME_MODULE_INDICATOR([mktime])
gl_MULTIARCH
+ gl_NPROC
gl_FUNC_GNU_STRFTIME
gl_PATHMAX
gl_FUNC_PIPE2
@@ -1221,6 +1223,8 @@ AC_DEFUN
lib/mkostemp.c
lib/mktime-internal.h
lib/mktime.c
+ lib/nproc.c
+ lib/nproc.h
lib/nstrftime.c
lib/open.c
lib/openat-priv.h
@@ -1370,6 +1374,7 @@ AC_DEFUN
m4/mode_t.m4
m4/multiarch.m4
m4/nocrash.m4
+ m4/nproc.m4
m4/nstrftime.m4
m4/off_t.m4
m4/open-cloexec.m4
diff --git a/m4/nproc.m4 b/m4/nproc.m4
new file mode 100644
index 0000000000..887c66bee8
--- /dev/null
+++ b/m4/nproc.m4
@@ -0,0 +1,54 @@
+# nproc.m4 serial 5
+dnl Copyright (C) 2009-2021 Free Software Foundation, Inc.
+dnl This file is free software; the Free Software Foundation
+dnl gives unlimited permission to copy and/or distribute it,
+dnl with or without modifications, as long as this notice is preserved.
+
+AC_DEFUN([gl_NPROC],
+[
+ gl_PREREQ_NPROC
+])
+
+# Prerequisites of lib/nproc.c.
+AC_DEFUN([gl_PREREQ_NPROC],
+[
+ dnl Persuade glibc <sched.h> to declare CPU_SETSIZE, CPU_ISSET etc.
+ AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])
+
+ AC_CHECK_HEADERS([sys/pstat.h sys/sysmp.h sys/param.h],,,
+ [AC_INCLUDES_DEFAULT])
+ dnl <sys/sysctl.h> requires <sys/param.h> on OpenBSD 4.0.
+ AC_CHECK_HEADERS([sys/sysctl.h],,,
+ [AC_INCLUDES_DEFAULT
+ #if HAVE_SYS_PARAM_H
+ # include <sys/param.h>
+ #endif
+ ])
+
+ AC_CHECK_FUNCS([sched_getaffinity sched_getaffinity_np \
+ pstat_getdynamic sysmp sysctl])
+
+ dnl Test whether sched_getaffinity has the expected declaration.
+ dnl glibc 2.3.[0-2]:
+ dnl int sched_getaffinity (pid_t, unsigned int, unsigned long int *);
+ dnl glibc 2.3.3:
+ dnl int sched_getaffinity (pid_t, cpu_set_t *);
+ dnl glibc >= 2.3.4:
+ dnl int sched_getaffinity (pid_t, size_t, cpu_set_t *);
+ if test $ac_cv_func_sched_getaffinity = yes; then
+ AC_CACHE_CHECK([for glibc compatible sched_getaffinity],
+ [gl_cv_func_sched_getaffinity3],
+ [AC_COMPILE_IFELSE(
+ [AC_LANG_PROGRAM(
+ [[#include <errno.h>
+ #include <sched.h>]],
+ [[sched_getaffinity (0, 0, (cpu_set_t *) 0);]])],
+ [gl_cv_func_sched_getaffinity3=yes],
+ [gl_cv_func_sched_getaffinity3=no])
+ ])
+ if test $gl_cv_func_sched_getaffinity3 = yes; then
+ AC_DEFINE([HAVE_SCHED_GETAFFINITY_LIKE_GLIBC], [1],
+ [Define to 1 if sched_getaffinity has a glibc compatible declaration.])
+ fi
+ fi
+])
diff --git a/src/process.c b/src/process.c
index 221d4c7f6c..746cdc0428 100644
--- a/src/process.c
+++ b/src/process.c
@@ -90,6 +90,7 @@ #define HAVE_LOCAL_SOCKETS
#include <c-ctype.h>
#include <flexmember.h>
+#include <nproc.h>
#include <sig2str.h>
#include <verify.h>
@@ -8212,6 +8213,20 @@ DEFUN ("process-attributes", Fprocess_attributes,
return system_process_attributes (pid);
}
+DEFUN ("num-processors", Fnum_processors, Snum_processors, 0, 1, 0,
+ doc: /* Return the number of processors, a positive integer.
+Each usable thread execution unit counts as a processor.
+By default, count the number of available processors,
+overridable via the OMP_NUM_THREADS environment variable.
+If optional argument QUERY is `current', ignore OMP_NUM_THREADS.
+If QUERY is `all', also count processors not available. */)
+ (Lisp_Object query)
+{
+ return make_uint (num_processors (EQ (query, Qall) ? NPROC_ALL
+ : EQ (query, Qcurrent) ? NPROC_CURRENT
+ : NPROC_CURRENT_OVERRIDABLE));
+}
+
#ifdef subprocesses
/* Arrange to catch SIGCHLD if this hasn't already been arranged.
Invoke this after init_process_emacs, and after glib and/or GNUstep
@@ -8472,6 +8487,8 @@ syms_of_process (void)
DEFSYM (Qpcpu, "pcpu");
DEFSYM (Qpmem, "pmem");
DEFSYM (Qargs, "args");
+ DEFSYM (Qall, "all");
+ DEFSYM (Qcurrent, "current");
DEFVAR_BOOL ("delete-exited-processes", delete_exited_processes,
doc: /* Non-nil means delete processes immediately when they exit.
@@ -8633,4 +8650,5 @@ #define ADD_SUBFEATURE(key, val) \
defsubr (&Sprocess_inherit_coding_system_flag);
defsubr (&Slist_system_processes);
defsubr (&Sprocess_attributes);
+ defsubr (&Snum_processors);
}
diff --git a/src/w32proc.c b/src/w32proc.c
index 702ea122e6..3b7d92a2aa 100644
--- a/src/w32proc.c
+++ b/src/w32proc.c
@@ -3878,6 +3878,7 @@ w32_compare_strings (const char *s1, const char *s2, char *locname,
return val - 2;
}
+/* FIXME: Remove, merging any of its special features into num-processors. */
DEFUN ("w32-get-nproc", Fw32_get_nproc,
Sw32_get_nproc, 0, 0, 0,
doc: /* Return the number of system's processor execution units. */)
diff --git a/test/src/process-tests.el b/test/src/process-tests.el
index e39f57d23b..44f3ea2fbb 100644
--- a/test/src/process-tests.el
+++ b/test/src/process-tests.el
@@ -946,5 +946,11 @@ process-async-https-with-delay
(when buf
(kill-buffer buf)))))
+(ert-deftest process-num-processors ()
+ "Sanity checks for num-processors."
+ (should (equal (num-processors) (num-processors)))
+ (should (integerp (num-processors)))
+ (should (< 0 (num-processors))))
+
(provide 'process-tests)
;;; process-tests.el ends here
--
2.30.2
