Re: [Use cpuops V1 05/11] core: Replace __get_cpu_var with__this_cpu_read if not used for an address.

[Christoph Lameter]

On Tue, 7 Dec 2010, Tejun Heo wrote:

> >  	if (&per_cpu(tasklet_hi_vec, cpu).head != per_cpu(tasklet_hi_vec, cpu).tail) {
> > -		*__get_cpu_var(tasklet_hi_vec).tail = per_cpu(tasklet_hi_vec, cpu).head;
> > -		__get_cpu_var(tasklet_hi_vec).tail = per_cpu(tasklet_hi_vec, cpu).tail;
> > +		*__this_cpuo_read(tasklet_hi_vec.tail) = per_cpu(tasklet_hi_vec, cpu).head;
> > +		__this_cpu_write(tasklet_hi_vec.tail, per_cpu(tasklet_hi_vec, cpu).tail;
>
> I don't think __this_cpuo_read() would build.

A CONFIG_HOTPLUG_CPU section.

Fix up CONFIG_HOTPLUG_CPU compilation

Signed-off-by: Christoph Lameter <cl@xxxxxxxxx>

Index: linux-2.6/kernel/softirq.c
===================================================================
--- linux-2.6.orig/kernel/softirq.c	2010-12-07 08:49:51.000000000 -0600
+++ linux-2.6/kernel/softirq.c	2010-12-07 08:49:32.000000000 -0600
@@ -810,10 +810,10 @@ static void takeover_tasklets(unsigned i
 	raise_softirq_irqoff(TASKLET_SOFTIRQ);

 	if (&per_cpu(tasklet_hi_vec, cpu).head != per_cpu(tasklet_hi_vec, cpu).tail) {
-		*__this_cpuo_read(tasklet_hi_vec.tail) = per_cpu(tasklet_hi_vec, cpu).head;
-		__this_cpu_write(tasklet_hi_vec.tail, per_cpu(tasklet_hi_vec, cpu).tail;
+		*__this_cpu_read(tasklet_hi_vec.tail) = per_cpu(tasklet_hi_vec, cpu).head;
+		__this_cpu_write(tasklet_hi_vec.tail, per_cpu(tasklet_hi_vec, cpu).tail);
 		per_cpu(tasklet_hi_vec, cpu).head = NULL;
-		per_cpu(tasklet_hi_vec, cpu).tail = &per_cpu(tasklet_hi_vec, cpu).head);
+		per_cpu(tasklet_hi_vec, cpu).tail = &per_cpu(tasklet_hi_vec, cpu).head;
 	}
 	raise_softirq_irqoff(HI_SOFTIRQ);



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