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 <cmetc...@tilera.com> Signed-off-by: Srivatsa S. Bhat <srivatsa.b...@linux.vnet.ibm.com> --- 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(); } /* _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev