The patch titled Subject: mm,thp: stop leaking unreleased file pages has been added to the -mm tree. Its filename is mmthp-stop-leaking-unreleased-file-pages.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/mmthp-stop-leaking-unreleased-file-pages.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/mmthp-stop-leaking-unreleased-file-pages.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Hugh Dickins <hughd@xxxxxxxxxx> Subject: mm,thp: stop leaking unreleased file pages When collapse_file() calls try_to_release_page(), it has already isolated the page: so if releasing buffers happens to fail (as it sometimes does), remember to putback_lru_page(): otherwise that page is left unreclaimable and unfreeable, and the file extent uncollapsible. Link: http://lkml.kernel.org/r/alpine.LSU.2.11.2005231837500.1766@eggly.anvils Fixes: 99cb0dbd47a1 ("mm,thp: add read-only THP support for (non-shmem) FS") Signed-off-by: Hugh Dickins <hughd@xxxxxxxxxx> Cc: Song Liu <songliubraving@xxxxxx> Cc: Rik van Riel <riel@xxxxxxxxxxx> Cc: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> [5.4+] Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/khugepaged.c | 1 + 1 file changed, 1 insertion(+) --- a/mm/khugepaged.c~mmthp-stop-leaking-unreleased-file-pages +++ a/mm/khugepaged.c @@ -1692,6 +1692,7 @@ static void collapse_file(struct mm_stru if (page_has_private(page) && !try_to_release_page(page, GFP_KERNEL)) { result = SCAN_PAGE_HAS_PRIVATE; + putback_lru_page(page); goto out_unlock; } _ Patches currently in -mm which might be from hughd@xxxxxxxxxx are mmthp-stop-leaking-unreleased-file-pages.patch mm-memcontrol-charge-swapin-pages-on-instantiation-fix.patch mm-vmstat-add-events-for-pmd-based-thp-migration-without-split-fix.patch