cpuplugd/cpu: Rework CPU management functions

Simplify the cpu management parts of cpuplugd code by introducing
functions from libutil and rework some logic to drop some assumptions
about how kernel assigns cpuids.
Right now cpuplugd assumes that the cpuids are always sequential and
there are no gaps in between, however kernel does not guarantee that.
Make cpuplugd compliant by traversing cpu sysfs entries instead.

Reviewed-by: Steffen Eiden <seiden@linux.ibm.com>
Reviewed-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Signed-off-by: Mete Durlu <meted@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
This commit is contained in:
Mete Durlu
2024-05-23 10:51:15 +02:00
committed by Jan Höppner
parent 0e4992da3a
commit c91d172c99
5 changed files with 195 additions and 224 deletions
+5 -29
View File
@@ -77,7 +77,7 @@ static void eval_cpu_rules(void)
{
double diffs[CPUSTATS], diffs_total, percent_factor;
char *procinfo_current, *procinfo_prev;
int cpu, nr_cpus, on_off;
int nr_cpus, on_off;
nr_cpus = get_numcpus();
procinfo_current = cpustat + history_current * cpustat_size;
@@ -172,40 +172,16 @@ static void eval_cpu_rules(void)
cpuplugd_debug("maximum cpu limit is reached\n");
return;
}
/* try to find a offline cpu */
for (cpu = 0; cpu < nr_cpus; cpu++)
if (is_online(cpu) == 0 && cpu_is_configured(cpu) != 0)
break;
if (cpu < nr_cpus) {
cpuplugd_debug("cpu with id %d is currently offline "
"and will be enabled\n", cpu);
if (hotplug(cpu) == -1)
cpuplugd_debug("unable to find a cpu which "
"can be enabled\n");
} else {
/*
* In case we tried to enable a cpu but this failed.
* This is the case if a cpu is deconfigured
*/
cpuplugd_debug("unable to find a cpu which can "
"be enabled\n");
}
if (hotplug_one_cpu())
cpuplugd_debug("unable to find a cpu which can be enabled\n");
} else if (on_off < 0) {
/* check cpu nr limit */
if (symbols.onumcpus <= cfg.cpu_min) {
cpuplugd_debug("minimum cpu limit is reached\n");
return;
}
/* try to find a online cpu */
for (cpu = get_numcpus() - 1; cpu >= 0; cpu--) {
if (is_online(cpu) != 0)
break;
}
if (cpu > 0) {
cpuplugd_debug("cpu with id %d is currently online "
"and will be disabled\n", cpu);
hotunplug(cpu);
}
if (hotunplug_one_cpu())
cpuplugd_debug("unable to find a cpu which can be disabled\n");
}
}