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Diffstat (limited to 'REORG.TODO/sysdeps/unix/sysv/linux/getsysstats.c')
-rw-r--r--REORG.TODO/sysdeps/unix/sysv/linux/getsysstats.c330
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diff --git a/REORG.TODO/sysdeps/unix/sysv/linux/getsysstats.c b/REORG.TODO/sysdeps/unix/sysv/linux/getsysstats.c
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index 0000000000..63e41100eb
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+++ b/REORG.TODO/sysdeps/unix/sysv/linux/getsysstats.c
@@ -0,0 +1,330 @@
+/* Determine various system internal values, Linux version.
+ Copyright (C) 1996-2017 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)
+
+
+/* Compute (num*mem_unit)/pagesize, but avoid overflowing long int.
+ In practice, mem_unit is never bigger than the page size, so after
+ the first loop it is 1. [In the kernel, it is initialized to
+ PAGE_SIZE in mm/page_alloc.c:si_meminfo(), and then in
+ kernel.sys.c:do_sysinfo() it is set to 1 if unsigned long can
+ represent all the sizes measured in bytes]. */
+static long int
+sysinfo_mempages (unsigned long int num, unsigned int mem_unit)
+{
+ unsigned long int ps = __getpagesize ();
+
+ while (mem_unit > 1 && ps > 1)
+ {
+ mem_unit >>= 1;
+ ps >>= 1;
+ }
+ num *= mem_unit;
+ while (ps > 1)
+ {
+ ps >>= 1;
+ num >>= 1;
+ }
+ return num;
+}
+
+/* Return the number of pages of total/available physical memory in
+ the system. This used to be done by parsing /proc/meminfo, but
+ that's unnecessarily expensive (and /proc is not always available).
+ The sysinfo syscall provides the same information, and has been
+ available at least since kernel 2.3.48. */
+long int
+__get_phys_pages (void)
+{
+ struct sysinfo info;
+
+ __sysinfo (&info);
+ return sysinfo_mempages (info.totalram, info.mem_unit);
+}
+weak_alias (__get_phys_pages, get_phys_pages)
+
+long int
+__get_avphys_pages (void)
+{
+ struct sysinfo info;
+
+ __sysinfo (&info);
+ return sysinfo_mempages (info.freeram, info.mem_unit);
+}
+weak_alias (__get_avphys_pages, get_avphys_pages)
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