359 lines
9.0 KiB
C
359 lines
9.0 KiB
C
/* Determine various system internal values, Linux version.
|
|
Copyright (C) 1996-2015 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.
|
|
|
|
The GNU C Library 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.
|
|
|
|
The GNU C Library 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 the GNU C Library; if not, see
|
|
<http://www.gnu.org/licenses/>. */
|
|
|
|
#include <alloca.h>
|
|
#include <assert.h>
|
|
#include <ctype.h>
|
|
#include <dirent.h>
|
|
#include <errno.h>
|
|
#include <fcntl.h>
|
|
#include <mntent.h>
|
|
#include <paths.h>
|
|
#include <stdio.h>
|
|
#include <stdio_ext.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include <unistd.h>
|
|
#include <sys/sysinfo.h>
|
|
|
|
#include <atomic.h>
|
|
#include <not-cancel.h>
|
|
|
|
|
|
/* How we can determine the number of available processors depends on
|
|
the configuration. There is currently (as of version 2.0.21) no
|
|
system call to determine the number. It is planned for the 2.1.x
|
|
series to add this, though.
|
|
|
|
One possibility to implement it for systems using Linux 2.0 is to
|
|
examine the pseudo file /proc/cpuinfo. Here we have one entry for
|
|
each processor.
|
|
|
|
But not all systems have support for the /proc filesystem. If it
|
|
is not available we simply return 1 since there is no way. */
|
|
|
|
|
|
/* Other architectures use different formats for /proc/cpuinfo. This
|
|
provides a hook for alternative parsers. */
|
|
#ifndef GET_NPROCS_PARSER
|
|
# define GET_NPROCS_PARSER(FD, BUFFER, CP, RE, BUFFER_END, RESULT) \
|
|
do \
|
|
{ \
|
|
(RESULT) = 0; \
|
|
/* Read all lines and count the lines starting with the string \
|
|
"processor". We don't have to fear extremely long lines since \
|
|
the kernel will not generate them. 8192 bytes are really \
|
|
enough. */ \
|
|
char *l; \
|
|
while ((l = next_line (FD, BUFFER, &CP, &RE, BUFFER_END)) != NULL) \
|
|
if (strncmp (l, "processor", 9) == 0) \
|
|
++(RESULT); \
|
|
} \
|
|
while (0)
|
|
#endif
|
|
|
|
|
|
static char *
|
|
next_line (int fd, char *const buffer, char **cp, char **re,
|
|
char *const buffer_end)
|
|
{
|
|
char *res = *cp;
|
|
char *nl = memchr (*cp, '\n', *re - *cp);
|
|
if (nl == NULL)
|
|
{
|
|
if (*cp != buffer)
|
|
{
|
|
if (*re == buffer_end)
|
|
{
|
|
memmove (buffer, *cp, *re - *cp);
|
|
*re = buffer + (*re - *cp);
|
|
*cp = buffer;
|
|
|
|
ssize_t n = read_not_cancel (fd, *re, buffer_end - *re);
|
|
if (n < 0)
|
|
return NULL;
|
|
|
|
*re += n;
|
|
|
|
nl = memchr (*cp, '\n', *re - *cp);
|
|
while (nl == NULL && *re == buffer_end)
|
|
{
|
|
/* Truncate too long lines. */
|
|
*re = buffer + 3 * (buffer_end - buffer) / 4;
|
|
n = read_not_cancel (fd, *re, buffer_end - *re);
|
|
if (n < 0)
|
|
return NULL;
|
|
|
|
nl = memchr (*re, '\n', n);
|
|
**re = '\n';
|
|
*re += n;
|
|
}
|
|
}
|
|
else
|
|
nl = memchr (*cp, '\n', *re - *cp);
|
|
|
|
res = *cp;
|
|
}
|
|
|
|
if (nl == NULL)
|
|
nl = *re - 1;
|
|
}
|
|
|
|
*cp = nl + 1;
|
|
assert (*cp <= *re);
|
|
|
|
return res == *re ? NULL : res;
|
|
}
|
|
|
|
|
|
int
|
|
__get_nprocs (void)
|
|
{
|
|
static int cached_result = -1;
|
|
static time_t timestamp;
|
|
|
|
time_t now = time (NULL);
|
|
time_t prev = timestamp;
|
|
atomic_read_barrier ();
|
|
if (now == prev && cached_result > -1)
|
|
return cached_result;
|
|
|
|
/* XXX Here will come a test for the new system call. */
|
|
|
|
const size_t buffer_size = __libc_use_alloca (8192) ? 8192 : 512;
|
|
char *buffer = alloca (buffer_size);
|
|
char *buffer_end = buffer + buffer_size;
|
|
char *cp = buffer_end;
|
|
char *re = buffer_end;
|
|
|
|
const int flags = O_RDONLY | O_CLOEXEC;
|
|
int fd = open_not_cancel_2 ("/sys/devices/system/cpu/online", flags);
|
|
char *l;
|
|
int result = 0;
|
|
if (fd != -1)
|
|
{
|
|
l = next_line (fd, buffer, &cp, &re, buffer_end);
|
|
if (l != NULL)
|
|
do
|
|
{
|
|
char *endp;
|
|
unsigned long int n = strtoul (l, &endp, 10);
|
|
if (l == endp)
|
|
{
|
|
result = 0;
|
|
break;
|
|
}
|
|
|
|
unsigned long int m = n;
|
|
if (*endp == '-')
|
|
{
|
|
l = endp + 1;
|
|
m = strtoul (l, &endp, 10);
|
|
if (l == endp)
|
|
{
|
|
result = 0;
|
|
break;
|
|
}
|
|
}
|
|
|
|
result += m - n + 1;
|
|
|
|
l = endp;
|
|
while (l < re && isspace (*l))
|
|
++l;
|
|
}
|
|
while (l < re);
|
|
|
|
close_not_cancel_no_status (fd);
|
|
|
|
if (result > 0)
|
|
goto out;
|
|
}
|
|
|
|
cp = buffer_end;
|
|
re = buffer_end;
|
|
result = 1;
|
|
|
|
/* The /proc/stat format is more uniform, use it by default. */
|
|
fd = open_not_cancel_2 ("/proc/stat", flags);
|
|
if (fd != -1)
|
|
{
|
|
result = 0;
|
|
|
|
while ((l = next_line (fd, buffer, &cp, &re, buffer_end)) != NULL)
|
|
/* The current format of /proc/stat has all the cpu* entries
|
|
at the front. We assume here that stays this way. */
|
|
if (strncmp (l, "cpu", 3) != 0)
|
|
break;
|
|
else if (isdigit (l[3]))
|
|
++result;
|
|
|
|
close_not_cancel_no_status (fd);
|
|
}
|
|
else
|
|
{
|
|
fd = open_not_cancel_2 ("/proc/cpuinfo", flags);
|
|
if (fd != -1)
|
|
{
|
|
GET_NPROCS_PARSER (fd, buffer, cp, re, buffer_end, result);
|
|
close_not_cancel_no_status (fd);
|
|
}
|
|
}
|
|
|
|
out:
|
|
cached_result = result;
|
|
atomic_write_barrier ();
|
|
timestamp = now;
|
|
|
|
return result;
|
|
}
|
|
weak_alias (__get_nprocs, get_nprocs)
|
|
|
|
|
|
/* On some architectures it is possible to distinguish between configured
|
|
and active cpus. */
|
|
int
|
|
__get_nprocs_conf (void)
|
|
{
|
|
/* XXX Here will come a test for the new system call. */
|
|
|
|
/* Try to use the sysfs filesystem. It has actual information about
|
|
online processors. */
|
|
DIR *dir = __opendir ("/sys/devices/system/cpu");
|
|
if (dir != NULL)
|
|
{
|
|
int count = 0;
|
|
struct dirent64 *d;
|
|
|
|
while ((d = __readdir64 (dir)) != NULL)
|
|
/* NB: the sysfs has d_type support. */
|
|
if (d->d_type == DT_DIR && strncmp (d->d_name, "cpu", 3) == 0)
|
|
{
|
|
char *endp;
|
|
unsigned long int nr = strtoul (d->d_name + 3, &endp, 10);
|
|
if (nr != ULONG_MAX && endp != d->d_name + 3 && *endp == '\0')
|
|
++count;
|
|
}
|
|
|
|
__closedir (dir);
|
|
|
|
return count;
|
|
}
|
|
|
|
int result = 1;
|
|
|
|
#ifdef GET_NPROCS_CONF_PARSER
|
|
/* If we haven't found an appropriate entry return 1. */
|
|
FILE *fp = fopen ("/proc/cpuinfo", "rce");
|
|
if (fp != NULL)
|
|
{
|
|
char buffer[8192];
|
|
|
|
/* No threads use this stream. */
|
|
__fsetlocking (fp, FSETLOCKING_BYCALLER);
|
|
GET_NPROCS_CONF_PARSER (fp, buffer, result);
|
|
fclose (fp);
|
|
}
|
|
#else
|
|
result = __get_nprocs ();
|
|
#endif
|
|
|
|
return result;
|
|
}
|
|
weak_alias (__get_nprocs_conf, get_nprocs_conf)
|
|
|
|
/* General function to get information about memory status from proc
|
|
filesystem. */
|
|
static long int
|
|
internal_function
|
|
phys_pages_info (const char *format)
|
|
{
|
|
char buffer[8192];
|
|
long int result = -1;
|
|
|
|
/* If we haven't found an appropriate entry return 1. */
|
|
FILE *fp = fopen ("/proc/meminfo", "rce");
|
|
if (fp != NULL)
|
|
{
|
|
/* No threads use this stream. */
|
|
__fsetlocking (fp, FSETLOCKING_BYCALLER);
|
|
|
|
result = 0;
|
|
/* Read all lines and count the lines starting with the
|
|
string "processor". We don't have to fear extremely long
|
|
lines since the kernel will not generate them. 8192
|
|
bytes are really enough. */
|
|
while (__fgets_unlocked (buffer, sizeof buffer, fp) != NULL)
|
|
if (sscanf (buffer, format, &result) == 1)
|
|
{
|
|
result /= (__getpagesize () / 1024);
|
|
break;
|
|
}
|
|
|
|
fclose (fp);
|
|
}
|
|
|
|
if (result == -1)
|
|
/* We cannot get the needed value: signal an error. */
|
|
__set_errno (ENOSYS);
|
|
|
|
return result;
|
|
}
|
|
|
|
|
|
/* Return the number of pages of physical memory in the system. There
|
|
is currently (as of version 2.0.21) no system call to determine the
|
|
number. It is planned for the 2.1.x series to add this, though.
|
|
|
|
One possibility to implement it for systems using Linux 2.0 is to
|
|
examine the pseudo file /proc/cpuinfo. Here we have one entry for
|
|
each processor.
|
|
|
|
But not all systems have support for the /proc filesystem. If it
|
|
is not available we return -1 as an error signal. */
|
|
long int
|
|
__get_phys_pages (void)
|
|
{
|
|
/* XXX Here will come a test for the new system call. */
|
|
|
|
return phys_pages_info ("MemTotal: %ld kB");
|
|
}
|
|
weak_alias (__get_phys_pages, get_phys_pages)
|
|
|
|
|
|
/* Return the number of available pages of physical memory in the
|
|
system. There is currently (as of version 2.0.21) no system call
|
|
to determine the number. It is planned for the 2.1.x series to add
|
|
this, though.
|
|
|
|
One possibility to implement it for systems using Linux 2.0 is to
|
|
examine the pseudo file /proc/cpuinfo. Here we have one entry for
|
|
each processor.
|
|
|
|
But not all systems have support for the /proc filesystem. If it
|
|
is not available we return -1 as an error signal. */
|
|
long int
|
|
__get_avphys_pages (void)
|
|
{
|
|
/* XXX Here will come a test for the new system call. */
|
|
|
|
return phys_pages_info ("MemFree: %ld kB");
|
|
}
|
|
weak_alias (__get_avphys_pages, get_avphys_pages)
|