Re: [PATCH 2/2] s390/mm: use ipte range to invalidate multiple page table entries
From: Martin Schwidefsky
Date: Wed Jul 06 2016 - 02:24:03 EST
On Wed, 06 Jul 2016 12:03:28 +0800
"Hillf Danton" <hillf.zj@xxxxxxxxxxxxxxx> wrote:
> >
> > +void ptep_invalidate_range(struct mm_struct *mm, unsigned long start,
> > + unsigned long end, pte_t *ptep)
> > +{
> > + unsigned long nr;
> > +
> > + if (!MACHINE_HAS_IPTE_RANGE || mm_has_pgste(mm))
> > + return;
> > + preempt_disable();
> > + nr = (end - start) >> PAGE_SHIFT;
> > + /* If the flush is likely to be local skip the ipte range */
> > + if (nr && !cpumask_equal(mm_cpumask(mm),
> > + cpumask_of(smp_processor_id())))
>
> s/smp/raw_smp/ to avoid adding schedule entry with page table
> lock held?
There can not be a schedule entry with either the page table lock held
or the preempt_disable() a few lines above.
> > + __ptep_ipte_range(start, nr - 1, ptep);
> > + preempt_enable();
> > +}
> > +EXPORT_SYMBOL(ptep_invalidate_range);
> > +
>
> thanks
> Hillf
>
--
blue skies,
Martin.
"Reality continues to ruin my life." - Calvin.