[PATCH v5 42/45] tile: Use get/put_online_cpus_atomic() to prevent CPU offline
From: Srivatsa S. Bhat <hidden>
Date: 2013-01-22 07:46:45
Also in:
linux-arch, linux-pm, linuxppc-dev, lkml, netdev
Subsystem:
the rest · Maintainer:
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. Cc: Chris Metcalf <redacted> Signed-off-by: Srivatsa S. Bhat <redacted> --- arch/tile/kernel/smp.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/arch/tile/kernel/smp.c b/arch/tile/kernel/smp.c
index cbc73a8..fb30624 100644
--- a/arch/tile/kernel/smp.c
+++ b/arch/tile/kernel/smp.c@@ -15,6 +15,7 @@ */ #include <linux/smp.h> +#include <linux/cpu.h> #include <linux/interrupt.h> #include <linux/io.h> #include <linux/irq.h>
@@ -82,9 +83,12 @@ void send_IPI_many(const struct cpumask *mask, int tag) void send_IPI_allbutself(int tag) { struct cpumask mask; + + get_online_cpus_atomic(); cpumask_copy(&mask, cpu_online_mask); cpumask_clear_cpu(smp_processor_id(), &mask); send_IPI_many(&mask, tag); + put_online_cpus_atomic(); } /*