You signed in with another tab or window. Reload to refresh your session.You signed out in another tab or window. Reload to refresh your session.You switched accounts on another tab or window. Reload to refresh your session.Dismiss alert
The mpstat output regarding the sum of the interrupts per core overflows under certain conditions. On my PC I ran mpstat under stress-ng --udp and I have output similar to this:
11:20:57 CPU intr/s
11:21:00 all 1880,00
11:21:00 0 395027,00
11:21:00 1 399987,33
11:21:00 2 365727,00
11:21:00 3 303783,33
I guess there is no overflow control over the sum over the cores.
How to reproduce the issue:
run mpstat with periodic reports and generate a interrupt critical workload.
The text was updated successfully, but these errors were encountered:
/*
* Read total number of interrupts received among all CPU.
* (this is the first value on the line "intr:" in the /proc/stat file).
*/
if (DISPLAY_IRQ_SUM(actflags)) {
read_stat_total_irq(st_irq[0]);
}
/*
***************************************************************************
* Read total number of interrupts from /proc/stat.
*
* IN:
* @st_irq Structure where total number of interrupts will be saved.
*
* OUT:
* @st_irq Structure with total number of interrupts.
***************************************************************************
*/
void read_stat_total_irq(struct stats_global_irq *st_irq)
{
FILE *fp;
char line[1024];
unsigned long long irq_nr;
if ((fp = fopen(STAT, "r")) == NULL)
return;
while (fgets(line, sizeof(line), fp) != NULL) {
if (!strncmp(line, "intr ", 5)) {
/* Read total number of interrupts received since system boot */
sscanf(line + 5, "%llu", &irq_nr);
st_irq->irq_nr = (unsigned int) irq_nr;
break;
}
}
fclose(fp);
}
I wasn't able to generate a sufficiently high workload on my system, but observing awk '/^intr/ { print $2 }' /proc/stat during your high workload might help to get a better understanding of this issue.
The mpstat output regarding the sum of the interrupts per core overflows under certain conditions. On my PC I ran mpstat under stress-ng --udp and I have output similar to this:
11:20:57 CPU intr/s
11:21:00 all 1880,00
11:21:00 0 395027,00
11:21:00 1 399987,33
11:21:00 2 365727,00
11:21:00 3 303783,33
I guess there is no overflow control over the sum over the cores.
How to reproduce the issue:
run mpstat with periodic reports and generate a interrupt critical workload.
The text was updated successfully, but these errors were encountered: