emo/procps
1
0
Fork 0
Code Issues Pull Requests Packages Releases Activity

Initialize smp_num_cpus only if really required

Browse Source 
Initialize smp_num_cpus only if really required

Signed-off-by: Werner Fink <werner@suse.de>
This commit is contained in:
Werner Fink 2011-04-15 15:53:20 +02:00
parent e646984924
commit aac0de8994
2 changed files with 35 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

32
proc/sysinfo.c
View File

@ -24,7 +24,9 @@
#include <netinet/in.h> /* htons */
#endif
#ifndef ZAP_SUSEONLY
long smp_num_cpus; /* number of CPUs */
#endif
#define BAD_OPEN_MESSAGE \
"Error: /proc must be mounted\n" \
@ -180,7 +182,11 @@ static void old_Hertz_hack(void){
setlocale(LC_NUMERIC, savelocale);
jiffies = user_j + nice_j + sys_j + other_j;
seconds = (up_1 + up_2) / 2;
#ifndef ZAP_SUSEONLY
h = (unsigned)( (double)jiffies/seconds/smp_num_cpus );
#else
h = (unsigned)( (double)jiffies/seconds/smp_num_cpus() );
#endif
/* actual values used by 2.4 kernels: 32 64 100 128 1000 1024 1200 */
switch(h){
case 9 ... 11 : Hertz = 10; break; /* S/390 (sometimes) */
@ -246,10 +252,34 @@ static int check_for_privs(void){
return !!rc;
}
#ifdef ZAP_SUSEONLY
long smp_num_cpus(void)
{
static long _smp_num_cpus=-1; /* number of CPUs */
if (_smp_num_cpus != -1)
return(_smp_num_cpus);
// ought to count CPUs in /proc/stat instead of relying
// on glibc, which foolishly tries to parse /proc/cpuinfo
//
// SourceForge has an old Alpha running Linux 2.2.20 that
// appears to have a non-SMP kernel on a 2-way SMP box.
// _SC_NPROCESSORS_CONF returns 2, resulting in HZ=512
// _SC_NPROCESSORS_ONLN returns 1, which should work OK
_smp_num_cpus = sysconf(_SC_NPROCESSORS_ONLN);
if(_smp_num_cpus<1) _smp_num_cpus=1; /* SPARC glibc is buggy */
return(_smp_num_cpus);
}
#endif
static void init_libproc(void) __attribute__((constructor));
static void init_libproc(void){
have_privs = check_for_privs();
init_Linux_version(); /* Must be called before we check code */
#ifndef ZAP_SUSEONLY
// ought to count CPUs in /proc/stat instead of relying
// on glibc, which foolishly tries to parse /proc/cpuinfo
//
@ -259,7 +289,7 @@ static void init_libproc(void){
// _SC_NPROCESSORS_ONLN returns 1, which should work OK
smp_num_cpus = sysconf(_SC_NPROCESSORS_ONLN);
if(smp_num_cpus<1) smp_num_cpus=1; /* SPARC glibc is buggy */
#endif
if(linux_version_code > LINUX_VERSION(2, 4, 0)){
Hertz = find_elf_note(AT_CLKTCK);
if(Hertz!=NOTE_NOT_FOUND) return;

4
proc/sysinfo.h
View File

@ -7,7 +7,11 @@
EXTERN_C_BEGIN
extern unsigned long long Hertz; /* clock tick frequency */
#ifndef ZAP_SUSEONLY
extern long smp_num_cpus; /* number of CPUs */
#else
extern long smp_num_cpus(void); /* number of CPUs */
#endif
extern int have_privs; /* boolean, true if setuid or similar */
#if 0