Commit 0a948df1 authored by Yu Liao's avatar Yu Liao
Browse files

sched/smt: fix unbalance sched_smt_present dec/inc 

hulk inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I7YBSW


CVE: NA

--------------------------------

If cpuset_cpu_inactive() fails in sched_cpu_deactivate(), the
cpu offline failed, but sched_smt_present is decreased before
calling sched_cpu_deactivate, it leads unbalance dec/inc, so
fix it by increasing sched_smt_present in the error path.

Signed-off-by: default avatarYang Yingliang <yangyingliang@huawei.com>
Signed-off-by: default avatarYu Liao <liaoyu15@huawei.com>
parent 4b99a7ce

kernel/sched/core.c

+4 −0
Original line number Diff line number Diff line
@@ -5897,6 +5897,10 @@ int sched_cpu_deactivate(unsigned int cpu) 


	ret = cpuset_cpu_inactive(cpu);

	if (ret) {

#ifdef CONFIG_SCHED_SMT

		if (cpumask_weight(cpu_smt_mask(cpu)) == 2)

			static_branch_inc_cpuslocked(&sched_smt_present);

#endif

		set_cpu_active(cpu, true);

		return ret;

	}