Messages in this thread Patch in this message | | | Date | Sun, 31 Aug 2008 10:33:49 -0700 | From | "Paul E. McKenney" <> | Subject | [PATCH] prevent sparc64 from invoking irq handlers on offline CPUs |
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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> ---
smp.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/arch/sparc64/kernel/smp.c b/arch/sparc64/kernel/smp.c index 743ccad..b83a683 100644 --- a/arch/sparc64/kernel/smp.c +++ b/arch/sparc64/kernel/smp.c @@ -1305,10 +1305,6 @@ int __cpu_disable(void) c->core_id = 0; c->proc_id = -1; - spin_lock(&call_lock); - cpu_clear(cpu, cpu_online_map); - spin_unlock(&call_lock); - smp_wmb(); /* Make sure no interrupts point to this cpu. */ @@ -1318,6 +1314,10 @@ int __cpu_disable(void) mdelay(1); local_irq_disable(); + spin_lock(&call_lock); + cpu_clear(cpu, cpu_online_map); + spin_unlock(&call_lock); + return 0; }
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