diff options
| -rw-r--r-- | ChangeLog | 3 | ||||
| -rw-r--r-- | sysdeps/unix/sysv/linux/getsysstats.c | 52 |
2 files changed, 52 insertions, 3 deletions
diff --git a/ChangeLog b/ChangeLog index 9cef65ae02..68409c9354 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,5 +1,8 @@ 2011-06-22 Ulrich Drepper <drepper@gmail.com> + * sysdeps/unix/sysv/linux/getsysstats.c (__get_nprocs): Use + /sys/devices/system/cpu/online if it is usable. + * sysdeps/unix/sysv/linux/getsysstats.c (__get_nprocs): Rate limit reading the information from the /proc filesystem to once a second. diff --git a/sysdeps/unix/sysv/linux/getsysstats.c b/sysdeps/unix/sysv/linux/getsysstats.c index a13b6e3e37..b74774ffe8 100644 --- a/sysdeps/unix/sysv/linux/getsysstats.c +++ b/sysdeps/unix/sysv/linux/getsysstats.c @@ -161,20 +161,65 @@ __get_nprocs () char *buffer_end = buffer + buffer_size; char *cp = buffer_end; char *re = buffer_end; - int result = 1; #ifdef O_CLOEXEC const int flags = O_RDONLY | O_CLOEXEC; #else const int flags = O_RDONLY; #endif + 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. */ - int fd = open_not_cancel_2 ("/proc/stat", flags); + fd = open_not_cancel_2 ("/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. */ @@ -195,6 +240,7 @@ __get_nprocs () } } + out: cached_result = result; atomic_write_barrier (); timestamp = ts.tv_sec; |