[PATCH v6 14/46] sched/rt: Use get/put_online_cpus_atomic() to prevent CPU offline
From: Srivatsa S. Bhat <hidden>
Date: 2013-02-18 12:42:28
Also in:
linux-arch, linux-arm-kernel, linux-pm, lkml, netdev
Subsystem:
scheduler, the rest · Maintainers:
Ingo Molnar, Peter Zijlstra, Juri Lelli, Vincent Guittot, Linus Torvalds
Once stop_machine() is gone from the CPU offline path, we won't be able to depend on preempt_disable() or local_irq_disable() to prevent CPUs from going offline from under us. Use the get/put_online_cpus_atomic() APIs to prevent CPUs from going offline, while invoking from atomic context. Signed-off-by: Srivatsa S. Bhat <redacted> --- kernel/sched/rt.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index 4f02b28..e546c98 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c@@ -6,6 +6,7 @@ #include "sched.h" #include <linux/slab.h> +#include <linux/cpu.h> static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun);
@@ -26,7 +27,9 @@ static enum hrtimer_restart sched_rt_period_timer(struct hrtimer *timer) if (!overrun) break; + get_online_cpus_atomic(); idle = do_sched_rt_period_timer(rt_b, overrun); + put_online_cpus_atomic(); } return idle ? HRTIMER_NORESTART : HRTIMER_RESTART;