| Date | Sun, 3 May 2020 20:10:36 -0700 | From | Matthew Wilcox <> | Subject | Re: [PATCH v3 18/25] mm: Allow large pages to be added to the page cache |
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On Wed, Apr 29, 2020 at 06:36:50AM -0700, Matthew Wilcox wrote: > @@ -886,7 +906,7 @@ static int __add_to_page_cache_locked(struct page *page, > /* Leave page->index set: truncation relies upon it */ > if (!huge) > mem_cgroup_cancel_charge(page, memcg, false); > - put_page(page); > + page_ref_sub(page, nr); > return xas_error(&xas); > } > ALLOW_ERROR_INJECTION(__add_to_page_cache_locked, ERRNO);
This is wrong. page_ref_sub() will not call __put_page() if the refcount gets to zero. What do people prefer?
- put_page(page);
(a) + put_thp(page);
(b) + put_page_nr(page, nr);
(c) + if (page_ref_sub_return(page, nr) == 0) + __put_page(page);
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