Re: [PATCH V2 2/7] mm: move MADV_FREE pages into LRU_INACTIVE_FILE list

[Hillf Danton]

On February 04, 2017 2:38 PM Hillf Danton wrote: 
> 
> On February 04, 2017 7:33 AM Shaohua Li wrote:
> > @@ -1404,6 +1401,8 @@ bool madvise_free_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma,
> >  		set_pmd_at(mm, addr, pmd, orig_pmd);
> >  		tlb_remove_pmd_tlb_entry(tlb, pmd, addr);
> >  	}
> > +
> > +	mark_page_lazyfree(page);
> >  	ret = true;
> >  out:
> >  	spin_unlock(ptl);
> 
> <snipped>
> 
> > -void deactivate_page(struct page *page)
> > -{
> > -	if (PageLRU(page) && PageActive(page) && !PageUnevictable(page)) {
> > -		struct pagevec *pvec = &get_cpu_var(lru_deactivate_pvecs);
> > +void mark_page_lazyfree(struct page *page)
> > + {
> > +	if (PageLRU(page) && PageAnon(page) && PageSwapBacked(page) &&
> > +	    !PageUnevictable(page)) {
> > +		struct pagevec *pvec = &get_cpu_var(lru_lazyfree_pvecs);
> >
> >  		get_page(page);
> >  		if (!pagevec_add(pvec, page) || PageCompound(page))
> > -			pagevec_lru_move_fn(pvec, lru_deactivate_fn, NULL);
> > -		put_cpu_var(lru_deactivate_pvecs);
> > +			pagevec_lru_move_fn(pvec, lru_lazyfree_fn, NULL);
> > +		put_cpu_var(lru_lazyfree_pvecs);
> >  	}
> >  }
> 
> You are not adding it but would you please try to fix or avoid flipping
> preempt count with page table lock hold?
> 
preempt_en/disable are embedded in spin_lock/unlock, so please
ignore my noise.

thanks
Hillf