On Mon 24-10-16 14:56:00, Johannes Weiner wrote:
> Hi Michal,
>
> On Mon, Oct 24, 2016 at 05:26:04PM +0200, Michal Hocko wrote:
> > @@ -155,44 +155,27 @@ static void page_cache_tree_delete(struct
> > address_space *mapping,
> > struct page *page, void *shadow)
> > {
> > struct radix_tree_node *node;
> > - unsigned long index;
> > - unsigned int offset;
> > - unsigned int tag;
> > void **slot;
> >
> > VM_BUG_ON(!PageLocked(page));
> >
> > __radix_tree_lookup(&mapping->page_tree, page->index, &node, &slot);
> >
> > - if (shadow) {
> > - mapping->nrshadows++;
> > - /*
> > - * Make sure the nrshadows update is committed before
> > - * the nrpages update so that final truncate racing
> > - * with reclaim does not see both counters 0 at the
> > - * same time and miss a shadow entry.
> > - */
> > - smp_wmb();
> > - }
> > - mapping->nrpages--;
> > + radix_tree_clear_tags(&mapping->page_tree, node, slot);
> >
> > if (!node) {
> > - /* Clear direct pointer tags in root node */
> > - mapping->page_tree.gfp_mask &= __GFP_BITS_MASK;
> > - radix_tree_replace_slot(slot, shadow);
> > - return;
> > - }
>
> There is no need to include the refactoring of the tag clearing in the
> stable backport. I already sent a simpler backport of this patch for
> 4.4 to Greg, attached here for reference:
I do not see this in 4.4 so maybe it's fallen through cracks. Yours
definitely looks easier and I will use it. I will post all 4 patches for
inclusion for stable tomorrow unless something else pops out.
Thanks for the review again!
--
Michal Hocko
SUSE Labs
