Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966288AbcJ2IPi (ORCPT ); Sat, 29 Oct 2016 04:15:38 -0400 Received: from mail-pf0-f194.google.com ([209.85.192.194]:33989 "EHLO mail-pf0-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966258AbcJ2IPc (ORCPT ); Sat, 29 Oct 2016 04:15:32 -0400 From: Ming Lei To: Jens Axboe , linux-kernel@vger.kernel.org Cc: linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org, Christoph Hellwig , "Kirill A . Shutemov" , Ming Lei , Jens Axboe Subject: [PATCH 46/60] block: deal with dirtying pages for multipage bvec Date: Sat, 29 Oct 2016 16:08:45 +0800 Message-Id: <1477728600-12938-47-git-send-email-tom.leiming@gmail.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1477728600-12938-1-git-send-email-tom.leiming@gmail.com> References: <1477728600-12938-1-git-send-email-tom.leiming@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2522 Lines: 103 In bio_check_pages_dirty(), bvec->bv_page is used as flag for marking if the page has been dirtied & released, and if no, it will be dirtied in deferred workqueue. With multipage bvec, we can't do that any more, so change the logic into checking all pages in one mp bvec, and only release all these pages if all are dirtied, otherwise dirty them all in deferred wrokqueue. Signed-off-by: Ming Lei --- block/bio.c | 43 ++++++++++++++++++++++++++++++++++++------- 1 file changed, 36 insertions(+), 7 deletions(-) diff --git a/block/bio.c b/block/bio.c index a9bf01784f37..8e5af6e8bba3 100644 --- a/block/bio.c +++ b/block/bio.c @@ -1597,8 +1597,9 @@ void bio_set_pages_dirty(struct bio *bio) { struct bio_vec *bvec; int i; + struct bvec_iter_all bia; - bio_for_each_segment_all(bvec, bio, i) { + bio_for_each_segment_all_rd(bvec, bio, i, bia) { struct page *page = bvec->bv_page; if (page && !PageCompound(page)) @@ -1606,16 +1607,26 @@ void bio_set_pages_dirty(struct bio *bio) } } +static inline void release_mp_bvec_pages(struct bio_vec *bvec) +{ + struct bio_vec bv; + struct bvec_iter iter; + + bvec_for_each_sp_bvec(bv, bvec, iter) + put_page(bv.bv_page); +} + static void bio_release_pages(struct bio *bio) { struct bio_vec *bvec; int i; + /* iterate each mp bvec */ bio_for_each_segment_all(bvec, bio, i) { struct page *page = bvec->bv_page; if (page) - put_page(page); + release_mp_bvec_pages(bvec); } } @@ -1659,20 +1670,38 @@ static void bio_dirty_fn(struct work_struct *work) } } +static inline void check_mp_bvec_pages(struct bio_vec *bvec, + int *nr_dirty, int *nr_pages) +{ + struct bio_vec bv; + struct bvec_iter iter; + + bvec_for_each_sp_bvec(bv, bvec, iter) { + struct page *page = bv.bv_page; + + if (PageDirty(page) || PageCompound(page)) + (*nr_dirty)++; + (*nr_pages)++; + } +} + void bio_check_pages_dirty(struct bio *bio) { struct bio_vec *bvec; int nr_clean_pages = 0; int i; - bio_for_each_segment_all(bvec, bio, i) { - struct page *page = bvec->bv_page; + bio_for_each_segment_all_wt(bvec, bio, i) { + int nr_dirty = 0, nr_pages = 0; + + check_mp_bvec_pages(bvec, &nr_dirty, &nr_pages); - if (PageDirty(page) || PageCompound(page)) { - put_page(page); + /* release all pages in the mp bvec if all are dirtied */ + if (nr_dirty == nr_pages) { + release_mp_bvec_pages(bvec); bvec->bv_page = NULL; } else { - nr_clean_pages++; + nr_clean_pages += nr_pages; } } -- 2.7.4