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obtain_clone_cpuid(): avoid locking while partitioned execution

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Change-Id: Iabb4784835be7dc9b2f555acc3a711fcc23ee7da
This commit is contained in:
Balazs Gerofi
2019-08-13 15:03:00 +09:00
committed by Masamichi Takagi
parent 51fe77cdae
commit 7aa2d64294
1 changed files with 8 additions and 3 deletions
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11
arch/arm64/kernel/syscall.c
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@ -59,9 +59,11 @@ int obtain_clone_cpuid(cpu_set_t *cpu_set, int use_last)
{
int min_queue_len = -1;
int cpu, min_cpu = -1, uti_cpu = -1;
unsigned long irqstate;
unsigned long irqstate = 0;
irqstate = ihk_mc_spinlock_lock(&runq_reservation_lock);
if (!cpu_local_var(current)->proc->nr_processes) {
irqstate = ihk_mc_spinlock_lock(&runq_reservation_lock);
}
/* Find the first allowed core with the shortest run queue */
for (cpu = 0; cpu < num_processors; ++cpu) {
@ -104,7 +106,10 @@ int obtain_clone_cpuid(cpu_set_t *cpu_set, int use_last)
__sync_fetch_and_add(&get_cpu_local_var(min_cpu)->runq_reserved,
1);
}
ihk_mc_spinlock_unlock(&runq_reservation_lock, irqstate);
if (!cpu_local_var(current)->proc->nr_processes) {
ihk_mc_spinlock_unlock(&runq_reservation_lock, irqstate);
}
return min_cpu;
}