Commit 4d084617 authored Sep 03, 2008 by Paul E. McKenney Committed by David S. Miller Sep 03, 2008

sparc64: Prevent sparc64 from invoking irq handlers on offline CPUs

Make sparc64 refrain from clearing a given to-be-offlined CPU's bit in the
cpu_online_mask until it has processed pending irqs. This change
prevents other CPUs from being blindsided by an apparently offline CPU
nevertheless changing globally visible state.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent e5bd1c3f

arch/sparc64/kernel/smp.c

+4 −4

Original line number	Diff line number	Diff line
		@@ -1303,10 +1303,6 @@ int __cpu_disable(void)
		c->core_id = 0;
		c->proc_id = -1;

		ipi_call_lock();
		cpu_clear(cpu, cpu_online_map);
		ipi_call_unlock();

		smp_wmb();

		/* Make sure no interrupts point to this cpu. */
		@@ -1316,6 +1312,10 @@ int __cpu_disable(void)
		mdelay(1);
		local_irq_disable();

		ipi_call_lock();
		cpu_clear(cpu, cpu_online_map);
		ipi_call_unlock();

		return 0;
		}