|
Ganglia uses float variables (double) to store the jiffies and the
jiffies sums. Analyzing how procps works with /proc/stat, I see it uses
integer values (unsined long long) to
store those same values, and uses float to store the percentage only. Theory is: Float numbers have a problem with precision and Ganglia is getting lost with big ppc64 numbers on its calculations. This patch changes libmetrics/linux/metrics.c to use integers (unsined long long) to store the jiffies and jiffies sums and floats (double) to store the calculated numbers only. Signed off by: Rafael Xavier <[email protected]> OBS: 1) This patch has been tested in a linux box, but not extensively. 2) It fixes it for linux only. The ideal approach would be to make the same changes for other architectures as well. --
| ||||
MM17 Hortolândia-SP, Brazildiff --git a/libmetrics/linux/metrics.c b/libmetrics/linux/metrics.c
index 7544f6e..83f706d 100644
--- a/libmetrics/linux/metrics.c
+++ b/libmetrics/linux/metrics.c
@@ -21,6 +21,8 @@
#define OSNAME "Linux"
#define OSNAME_LEN strlen(OSNAME)
+#define JT unsigned long long
+
/* /proc/net/dev hash table stuff */
typedef struct net_dev_stats net_dev_stats;
struct net_dev_stats {
@@ -616,11 +618,11 @@ os_release_func ( void )
/*
* A helper function to return the total number of cpu jiffies
*/
-unsigned long
+JT
total_jiffies_func ( void )
{
char *p;
- unsigned long user_jiffies, nice_jiffies, system_jiffies, idle_jiffies,
+ JT user_jiffies, nice_jiffies, system_jiffies, idle_jiffies,
wio_jiffies, irq_jiffies, sirq_jiffies;
p = update_file(&proc_stat);
@@ -655,8 +657,8 @@ cpu_user_func ( void )
char *p;
static g_val_t val;
static struct timeval stamp={0,0};
- static double last_user_jiffies, user_jiffies,
- last_total_jiffies, total_jiffies, diff;
+ static JT last_user_jiffies, user_jiffies,
+ last_total_jiffies, total_jiffies, diff;
p = update_file(&proc_stat);
if((proc_stat.last_read.tv_sec != stamp.tv_sec) &&
@@ -670,7 +672,7 @@ cpu_user_func ( void )
diff = user_jiffies - last_user_jiffies;
if ( diff )
- val.f = (diff/(total_jiffies - last_total_jiffies))*100;
+ val.f = ((double)diff/(double)(total_jiffies - last_total_jiffies))*100.0;
else
val.f = 0.0;
@@ -687,8 +689,8 @@ cpu_nice_func ( void )
char *p;
static g_val_t val;
static struct timeval stamp={0,0};
- static double last_nice_jiffies, nice_jiffies,
- last_total_jiffies, total_jiffies, diff;
+ static JT last_nice_jiffies, nice_jiffies,
+ last_total_jiffies, total_jiffies, diff;
p = update_file(&proc_stat);
if((proc_stat.last_read.tv_sec != stamp.tv_sec) &&
@@ -703,7 +705,7 @@ cpu_nice_func ( void )
diff = (nice_jiffies - last_nice_jiffies);
if ( diff )
- val.f = (diff/(total_jiffies - last_total_jiffies))*100;
+ val.f = ((double)diff/(double)(total_jiffies - last_total_jiffies))*100.0;
else
val.f = 0.0;
@@ -720,8 +722,8 @@ cpu_system_func ( void )
char *p;
static g_val_t val;
static struct timeval stamp={0,0};
- static double last_system_jiffies, system_jiffies,
- last_total_jiffies, total_jiffies, diff;
+ static JT last_system_jiffies, system_jiffies,
+ last_total_jiffies, total_jiffies, diff;
p = update_file(&proc_stat);
if((proc_stat.last_read.tv_sec != stamp.tv_sec) &&
@@ -745,7 +747,7 @@ cpu_system_func ( void )
diff = system_jiffies - last_system_jiffies;
if ( diff )
- val.f = (diff/(total_jiffies - last_total_jiffies))*100;
+ val.f = ((double)diff/(double)(total_jiffies - last_total_jiffies))*100.0;
else
val.f = 0.0;
@@ -762,8 +764,8 @@ cpu_idle_func ( void )
char *p;
static g_val_t val;
static struct timeval stamp={0,0};
- static double last_idle_jiffies, idle_jiffies,
- last_total_jiffies, total_jiffies, diff;
+ static JT last_idle_jiffies, idle_jiffies,
+ last_total_jiffies, total_jiffies, diff;
p = update_file(&proc_stat);
if((proc_stat.last_read.tv_sec != stamp.tv_sec) &&
@@ -780,7 +782,7 @@ cpu_idle_func ( void )
diff = idle_jiffies - last_idle_jiffies;
if ( diff )
- val.f = (diff/(total_jiffies - last_total_jiffies))*100;
+ val.f = ((double)diff/(double)(total_jiffies - last_total_jiffies))*100.0;
else
val.f = 0.0;
@@ -797,7 +799,7 @@ cpu_aidle_func ( void )
{
char *p;
g_val_t val;
- double idle_jiffies, total_jiffies;
+ JT idle_jiffies, total_jiffies;
p = update_file(&proc_stat);
@@ -805,10 +807,10 @@ cpu_aidle_func ( void )
p = skip_token(p);
p = skip_token(p);
p = skip_token(p);
- idle_jiffies = strtod( p , (char **)NULL );
+ idle_jiffies = (JT) strtod( p , (char **)NULL );
total_jiffies = total_jiffies_func();
- val.f = (idle_jiffies/total_jiffies)*100;
+ val.f = ((double)(idle_jiffies/total_jiffies))*100.0;
return val;
}
@@ -818,8 +820,8 @@ cpu_wio_func ( void )
char *p;
static g_val_t val;
static struct timeval stamp={0,0};
- static double last_wio_jiffies, wio_jiffies,
- last_total_jiffies, total_jiffies, diff;
+ static JT last_wio_jiffies, wio_jiffies,
+ last_total_jiffies, total_jiffies, diff;
if (num_cpustates == NUM_CPUSTATES_24X) {
val.f = 0.;
@@ -842,7 +844,7 @@ cpu_wio_func ( void )
diff = wio_jiffies - last_wio_jiffies;
if ( diff )
- val.f = (diff/(total_jiffies - last_total_jiffies))*100;
+ val.f = ((double)diff/(double)(total_jiffies - last_total_jiffies))*100.0;
else
val.f = 0.0;
@@ -860,8 +862,8 @@ cpu_intr_func ( void )
char *p;
static g_val_t val;
static struct timeval stamp={0,0};
- static double last_intr_jiffies, intr_jiffies,
- last_total_jiffies, total_jiffies, diff;
+ static JT last_intr_jiffies, intr_jiffies,
+ last_total_jiffies, total_jiffies, diff;
if (num_cpustates == NUM_CPUSTATES_24X) {
val.f = 0.;
@@ -885,7 +887,7 @@ cpu_intr_func ( void )
diff = intr_jiffies - last_intr_jiffies;
if ( diff )
- val.f = (diff/(total_jiffies - last_total_jiffies))*100;
+ val.f = ((double)diff/(double)(total_jiffies - last_total_jiffies))*100.0;
else
val.f = 0.0;
@@ -903,8 +905,8 @@ cpu_sintr_func ( void )
char *p;
static g_val_t val;
static struct timeval stamp={0,0};
- static double last_sintr_jiffies, sintr_jiffies,
- last_total_jiffies, total_jiffies, diff;
+ static JT last_sintr_jiffies, sintr_jiffies,
+ last_total_jiffies, total_jiffies, diff;
if (num_cpustates == NUM_CPUSTATES_24X) {
val.f = 0.;
@@ -929,7 +931,7 @@ cpu_sintr_func ( void )
diff = sintr_jiffies - last_sintr_jiffies;
if ( diff )
- val.f = (diff/(total_jiffies - last_total_jiffies))*100;
+ val.f = ((double)diff/(double)(total_jiffies - last_total_jiffies))*100.0;
else
val.f = 0.0;
------------------------------------------------------------------------------
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