- mutex_lock(&pmc_reserve_mutex);
- for (i = 0; i < ARRAY_SIZE(x86_pmu.lbr_exclusive); i++) {
- if (i != what && atomic_read(&x86_pmu.lbr_exclusive[i]))
- goto out;
+ if (!atomic_inc_not_zero(&x86_pmu.lbr_exclusive[what])) {
+ mutex_lock(&pmc_reserve_mutex);
+ for (i = 0; i < ARRAY_SIZE(x86_pmu.lbr_exclusive); i++) {
+ if (i != what && atomic_read(&x86_pmu.lbr_exclusive[i]))
+ goto fail_unlock;
+ }
+ atomic_inc(&x86_pmu.lbr_exclusive[what]);
+ mutex_unlock(&pmc_reserve_mutex);