Re: [PATCH 3/9] mm: introduce api for split page table lock for PMD level

["Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>]

Peter Zijlstra wrote:
> On Fri, Sep 13, 2013 at 04:06:10PM +0300, Kirill A. Shutemov wrote:
> > Basic api, backed by mm->page_table_lock for now. Actual implementation
> > will be added later.
> > 
> > Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
> > Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> > ---
> >  include/linux/mm.h | 13 +++++++++++++
> >  1 file changed, 13 insertions(+)
> > 
> > diff --git a/include/linux/mm.h b/include/linux/mm.h
> > index 6cf8ddb..d4361e7 100644
> > --- a/include/linux/mm.h
> > +++ b/include/linux/mm.h
> > @@ -1294,6 +1294,19 @@ static inline void pgtable_page_dtor(struct page *page)
> >  	((unlikely(pmd_none(*(pmd))) && __pte_alloc_kernel(pmd, address))? \
> >  		NULL: pte_offset_kernel(pmd, address))
> >  
> > +static inline spinlock_t *huge_pmd_lockptr(struct mm_struct *mm, pmd_t *pmd)
> > +{
> > +	return &mm->page_table_lock;
> > +}
> > +
> > +
> > +static inline spinlock_t *huge_pmd_lock(struct mm_struct *mm, pmd_t *pmd)
> > +{
> > +	spinlock_t *ptl = huge_pmd_lockptr(mm, pmd);
> > +	spin_lock(ptl);
> > +	return ptl;
> > +}
> 
> Why not call the thing pmd_lock()? The pmd bit differentiates it from
> pte_lock() enough IMIO.

Okay, will rename it.

-- 
 Kirill A. Shutemov