ANDROID: kernel: cgroup: cpuset: Clear cpus_requested for empty buf

update_cpumask had a special case for empty buf which
did not update cpus_requested. This change reduces
differences (only to parsing) in empty/non-empty codepaths
to make them consistent.

Bug: 120444281
Fixes: 4803def4e0b2 ("ANDROID: cpuset: Make cpusets restore on hotplug")
Test: check that writes to /dev/cpuset/background/tasks
Test: work as expected, e.g.:
Test: echo $$ > /dev/cpuset/background/tasks
Test: echo > /dev/cpuset/background/tasks
Signed-off-by: Roman Kiryanov <rkir@google.com>
Change-Id: I49d320ea046636ec38bd23f053317abc59f64f8e
This commit is contained in:
Roman Kiryanov 2019-06-19 11:11:59 -07:00 committed by codeworkx
parent 4ff5a444cd
commit abc093a14d

View file

@ -954,24 +954,24 @@ static int update_cpumask(struct cpuset *cs, struct cpuset *trialcs,
return -EACCES;
/*
* An empty cpus_allowed is ok only if the cpuset has no tasks.
* An empty cpus_requested is ok only if the cpuset has no tasks.
* Since cpulist_parse() fails on an empty mask, we special case
* that parsing. The validate_change() call ensures that cpusets
* with tasks have cpus.
*/
if (!*buf) {
cpumask_clear(trialcs->cpus_allowed);
cpumask_clear(trialcs->cpus_requested);
} else {
retval = cpulist_parse(buf, trialcs->cpus_requested);
if (retval < 0)
return retval;
if (!cpumask_subset(trialcs->cpus_requested, cpu_present_mask))
return -EINVAL;
cpumask_and(trialcs->cpus_allowed, trialcs->cpus_requested, cpu_active_mask);
}
if (!cpumask_subset(trialcs->cpus_requested, cpu_present_mask))
return -EINVAL;
cpumask_and(trialcs->cpus_allowed, trialcs->cpus_requested, cpu_active_mask);
/* Nothing to do if the cpus didn't change */
if (cpumask_equal(cs->cpus_requested, trialcs->cpus_requested))
return 0;