+ mm-filemap-fix-page-cache-removal-for-arbitrary-sized-thps.patch added to -mm tree

+ mm-filemap-fix-page-cache-removal-for-arbitrary-sized-thps.patch added to -mm tree

[akpm]

The patch titled
     Subject: mm/filemap: fix page cache removal for arbitrary sized THPs
has been added to the -mm tree.  Its filename is
     mm-filemap-fix-page-cache-removal-for-arbitrary-sized-thps.patch

This patch should soon appear at
    https://ozlabs.org/~akpm/mmots/broken-out/mm-filemap-fix-page-cache-removal-for-arbitrary-sized-thps.patch
and later at
    https://ozlabs.org/~akpm/mmotm/broken-out/mm-filemap-fix-page-cache-removal-for-arbitrary-sized-thps.patch

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------------------------------------------------------
From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Subject: mm/filemap: fix page cache removal for arbitrary sized THPs

Patch series "Remove assumptions of THP size".

There are a number of places in the VM which assume that a THP is a PMD in
size.  That's true today, and remains true after this patch series, but
this is a prerequisite for switching to arbitrary-sized THPs. 
thp_nr_pages() still returns either HPAGE_PMD_NR or 1, but will be changed
later.


This patch (of 11):

page_cache_free_page() assumes THPs are PMD_SIZE; fix that assumption.

Link: https://lkml.kernel.org/r/20200908195539.25896-1-willy@infradead.org
Link: https://lkml.kernel.org/r/20200908195539.25896-2-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Huang Ying <ying.huang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/filemap.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/mm/filemap.c~mm-filemap-fix-page-cache-removal-for-arbitrary-sized-thps
+++ a/mm/filemap.c
@@ -249,7 +249,7 @@ static void page_cache_free_page(struct
 		freepage(page);
 
 	if (PageTransHuge(page) && !PageHuge(page)) {
-		page_ref_sub(page, HPAGE_PMD_NR);
+		page_ref_sub(page, thp_nr_pages(page));
 		VM_BUG_ON_PAGE(page_count(page) <= 0, page);
 	} else {
 		put_page(page);
_

Patches currently in -mm which might be from willy@infradead.org are

mm-debug-do-not-dereference-i_ino-blindly.patch
mm-account-pmd-tables-like-pte-tables.patch
mm-move-pagedoublemap-bit.patch
mm-simplify-pagedoublemap-with-pf_second-policy.patch
xarray-add-xa_get_order.patch
xarray-add-xas_split.patch
mm-filemap-fix-storing-to-a-thp-shadow-entry.patch
mm-filemap-fix-page-cache-removal-for-arbitrary-sized-thps.patch
mm-memory-remove-page-fault-assumption-of-compound-page-size.patch
mm-page_owner-change-split_page_owner-to-take-a-count.patch
mm-huge_memory-fix-page_trans_huge_mapcount-assumption-of-thp-size.patch
mm-huge_memory-fix-can_split_huge_page-assumption-of-thp-size.patch
mm-rmap-fix-assumptions-of-thp-size.patch
mm-truncate-fix-truncation-for-pages-of-arbitrary-size.patch
mm-page-writeback-support-tail-pages-in-wait_for_stable_page.patch
mm-vmscan-allow-arbitrary-sized-pages-to-be-paged-out.patch
mm-readahead-add-define_readahead.patch
mm-readahead-make-page_cache_ra_unbounded-take-a-readahead_control.patch
mm-readahead-make-do_page_cache_ra-take-a-readahead_control.patch
mm-readahead-add-page_cache_sync_ra-and-page_cache_async_ra.patch
harden-autofs-ioctl-table.patch