Re: [PATCH 1/2] mm, thp: introduce dedicated transparent huge page allocation interfaces

[Du, Changbin]

On Tue, Oct 17, 2017 at 02:12:46PM +0300, Kirill A. Shutemov wrote:
> On Mon, Oct 16, 2017 at 05:19:16PM +0800, changbin.du@xxxxxxxxx wrote:
> > @@ -501,6 +501,45 @@ void prep_transhuge_page(struct page *page)
> >  	set_compound_page_dtor(page, TRANSHUGE_PAGE_DTOR);
> >  }
> >  
> > +struct page *alloc_transhuge_page_vma(gfp_t gfp_mask,
> > +		struct vm_area_struct *vma, unsigned long addr)
> > +{
> > +	struct page *page;
> > +
> > +	page = alloc_pages_vma(gfp_mask | __GFP_COMP, HPAGE_PMD_ORDER,
> > +			       vma, addr, numa_node_id(), true);
> > +	if (unlikely(!page))
> > +		return NULL;
> > +	prep_transhuge_page(page);
> > +	return page;
> > +}
> > +
> > +struct page *alloc_transhuge_page_nodemask(gfp_t gfp_mask,
> > +		int preferred_nid, nodemask_t *nmask)
> > +{
> > +	struct page *page;
> > +
> > +	page = __alloc_pages_nodemask(gfp_mask | __GFP_COMP, HPAGE_PMD_ORDER,
> > +				      preferred_nid, nmask);
> > +	if (unlikely(!page))
> > +		return NULL;
> > +	prep_transhuge_page(page);
> > +	return page;
> > +}
> > +
> > +struct page *alloc_transhuge_page(gfp_t gfp_mask)
> > +{
> > +	struct page *page;
> > +
> > +	VM_BUG_ON(!(gfp_mask & __GFP_COMP));
> 
> Why do you check for __GFP_COMP only in this helper?
> 
> > +	page = alloc_pages(gfp_mask | __GFP_COMP, HPAGE_PMD_ORDER);
> 
> And still apply __GFP_COMP anyway?
>
This is a mistake, will removed. Thanks.

> > +	if (unlikely(!page))
> > +		return NULL;
> > +	prep_transhuge_page(page);
> > +	return page;
> > +}
> > +
> >  unsigned long __thp_get_unmapped_area(struct file *filp, unsigned long len,
> >  		loff_t off, unsigned long flags, unsigned long size)
> >  {
> 
> -- 
>  Kirill A. Shutemov

-- 
Thanks,
Changbin Du

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