/* Determine various system internal values, Linux version. Copyright (C) 1996-2001, 2002, 2003, 2006, 2007 Free Software Foundation, Inc. This file is part of the GNU C Library. Contributed by Ulrich Drepper , 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, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* 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(FP, BUFFER, 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. */ \ while (fgets_unlocked (BUFFER, sizeof (BUFFER), FP) != NULL) \ if (strncmp (BUFFER, "processor", 9) == 0) \ ++(RESULT); \ } \ while (0) #endif int __get_nprocs () { /* XXX Here will come a test for the new system call. */ char buffer[8192]; int result = 1; /* The /proc/stat format is more uniform, use it by default. */ FILE *fp = fopen ("/proc/stat", "rc"); if (fp != NULL) { /* No threads use this stream. */ __fsetlocking (fp, FSETLOCKING_BYCALLER); result = 0; while (fgets_unlocked (buffer, sizeof (buffer), fp) != NULL) if (strncmp (buffer, "cpu", 3) == 0 && isdigit (buffer[3])) ++result; fclose (fp); } else { fp = fopen ("/proc/cpuinfo", "rc"); if (fp != NULL) { /* No threads use this stream. */ __fsetlocking (fp, FSETLOCKING_BYCALLER); GET_NPROCS_PARSER (fp, buffer, result); fclose (fp); } } 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 () { /* 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", "rc"); 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", "rc"); 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 () { /* 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 () { /* 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)