stop_machine: Avoid a sleep and wakeup in stop_one_cpu()

[cascardo/linux.git] / kernel / stop_machine.c

diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c
index 4a1ca5f..082e71f 100644 (file)
--- a/kernel/stop_machine.c
+++ b/kernel/stop_machine.c
@@ -126,6 +126,11 @@ int stop_one_cpu(unsigned int cpu, cpu_stop_fn_t fn, void *arg)
        cpu_stop_init_done(&done, 1);
        if (!cpu_stop_queue_work(cpu, &work))
                return -ENOENT;
+       /*
+        * In case @cpu == smp_proccessor_id() we can avoid a sleep+wakeup
+        * cycle by doing a preemption:
+        */
+       cond_resched();
        wait_for_completion(&done.completion);
        return done.ret;
 }