Re: [PATCH v6 7/8] mm: only IPI CPUs to drain local pages if theyexist

[Michal Nazarewicz]

On Mon, 09 Jan 2012 17:35:26 +0100, Christoph Lameter <cl@xxxxxxxxx> wrote:

> On Sun, 8 Jan 2012, Gilad Ben-Yossef wrote:
>
> > @@ -67,6 +67,14 @@ DEFINE_PER_CPU(int, numa_node);
> >  EXPORT_PER_CPU_SYMBOL(numa_node);
> >  #endif
> >
> > +/*
> > + * A global cpumask of CPUs with per-cpu pages that gets
> > + * recomputed on each drain. We use a global cpumask
> > + * here to avoid allocation on direct reclaim code path
> > + * for CONFIG_CPUMASK_OFFSTACK=y
> > + */
> > +static cpumask_var_t cpus_with_pcps;
>
> Move the static definition into drain_all_pages()?

This is initialised in setup_per_cpu_pageset() so it needs to be file scoped.

> > +
> >  #ifdef CONFIG_HAVE_MEMORYLESS_NODES
> >  /*
> >   * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
> > @@ -1097,7 +1105,19 @@ void drain_local_pages(void *arg)
> >   */
> >  void drain_all_pages(void)
> >  {
> > -	on_each_cpu(drain_local_pages, NULL, 1);
> > +	int cpu;
> > +	struct per_cpu_pageset *pcp;
> > +	struct zone *zone;
> > +
> > +	for_each_online_cpu(cpu)
> > +		for_each_populated_zone(zone) {
> > +			pcp = per_cpu_ptr(zone->pageset, cpu);
> > +			if (pcp->pcp.count)
> > +				cpumask_set_cpu(cpu, cpus_with_pcps);
> > +			else
> > +				cpumask_clear_cpu(cpu, cpus_with_pcps);
> > +		}
> > +	on_each_cpu_mask(cpus_with_pcps, drain_local_pages, NULL, 1);
> >  }
> >
> >  #ifdef CONFIG_HIBERNATION
> > @@ -3601,6 +3621,10 @@ static void setup_zone_pageset(struct zone *zone)
> >  void __init setup_per_cpu_pageset(void)
> >  {
> >  	struct zone *zone;
> > +	int ret;
> > +
> > +	ret = zalloc_cpumask_var(&cpus_with_pcps, GFP_KERNEL);
> > +	BUG_ON(!ret);
> >
> >  	for_each_populated_zone(zone)
> >  		setup_zone_pageset(zone);
>
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..o | Computer Science,  MichaÅ âmina86â Nazarewicz    (o o)
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