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Shutemov" Content-Type: text/plain; charset="UTF-8" X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Thu, Oct 17, 2019 at 9:42 AM Song Liu wrote: > > From: "Kirill A. Shutemov" > > Once a THP is added to the page cache, it cannot be dropped via > /proc/sys/vm/drop_caches. Fix this issue with proper handling in > invalidate_mapping_pages(). > > Fixes: 99cb0dbd47a1 ("mm,thp: add read-only THP support for (non-shmem) FS") > Signed-off-by: Kirill A. Shutemov > Tested-by: Song Liu > Signed-off-by: Song Liu > --- > mm/truncate.c | 12 ++++++++++++ > 1 file changed, 12 insertions(+) > > diff --git a/mm/truncate.c b/mm/truncate.c > index 8563339041f6..dd9ebc1da356 100644 > --- a/mm/truncate.c > +++ b/mm/truncate.c > @@ -592,6 +592,16 @@ unsigned long invalidate_mapping_pages(struct address_space *mapping, > unlock_page(page); > continue; > } > + > + /* Take a pin outside pagevec */ > + get_page(page); > + > + /* > + * Drop extra pins before trying to invalidate > + * the huge page. > + */ > + pagevec_remove_exceptionals(&pvec); > + pagevec_release(&pvec); Shall we skip the outer pagevec_remove_exceptions() if it has been done here? > } > > ret = invalidate_inode_page(page); > @@ -602,6 +612,8 @@ unsigned long invalidate_mapping_pages(struct address_space *mapping, > */ > if (!ret) > deactivate_file_page(page); > + if (PageTransHuge(page)) > + put_page(page); > count += ret; > } > pagevec_remove_exceptionals(&pvec); > -- > 2.17.1 > >