mirror/glibc
2
0
Fork 0
mirror of git://sourceware.org/git/glibc.git synced 2025-01-30 12:31:53 +08:00
Code Issues Packages Projects Releases Wiki Activity

linux: Use /proc/stat fallback for __get_nprocs_conf (BZ #28624)

Browse Source 
The /proc/statm fallback was removed by f13fb81ad3 if sysfs is
not available, reinstate it.

Checked on x86_64-linux-gnu.
(cherry-picked from commit 137ed5ac44)
This commit is contained in:
Adhemerval Zanella 2021-11-25 09:12:00 -03:00
parent bfe68fe3c4
commit f988b7f228
1 changed files with 35 additions and 25 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

60
sysdeps/unix/sysv/linux/getsysstats.c
View File

@ -108,6 +108,37 @@ next_line (int fd, char *const buffer, char **cp, char **re,
return res == *re ? NULL : res;
}
static int
get_nproc_stat (char *buffer, size_t buffer_size)
{
char *buffer_end = buffer + buffer_size;
char *cp = buffer_end;
char *re = buffer_end;
/* Default to an SMP system in case we cannot obtain an accurate
number. */
int result = 2;
const int flags = O_RDONLY | O_CLOEXEC;
int fd = __open_nocancel ("/proc/stat", flags);
if (fd != -1)
{
result = 0;
char *l;
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_nocancel_nostatus (fd);
}
return result;
}
int
__get_nprocs (void)
@ -163,30 +194,7 @@ __get_nprocs (void)
return result;
}
cp = buffer_end;
re = buffer_end;
/* Default to an SMP system in case we cannot obtain an accurate
number. */
result = 2;
fd = __open_nocancel ("/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_nocancel_nostatus (fd);
}
return result;
return get_nproc_stat (buffer, buffer_size);
}
libc_hidden_def (__get_nprocs)
weak_alias (__get_nprocs, get_nprocs)
@ -220,7 +228,9 @@ __get_nprocs_conf (void)
return count;
}
return 1;
enum { buffer_size = 1024 };
char buffer[buffer_size];
return get_nproc_stat (buffer, buffer_size);
}
libc_hidden_def (__get_nprocs_conf)
weak_alias (__get_nprocs_conf, get_nprocs_conf)