From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755929AbcL0QCE (ORCPT ); Tue, 27 Dec 2016 11:02:04 -0500 Received: from mail-pg0-f68.google.com ([74.125.83.68]:34668 "EHLO mail-pg0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755686AbcL0QB3 (ORCPT ); Tue, 27 Dec 2016 11:01:29 -0500 From: Ming Lei To: Jens Axboe , linux-kernel@vger.kernel.org Cc: linux-block@vger.kernel.org, Christoph Hellwig , Ming Lei , Jens Axboe Subject: [PATCH v1 22/54] block: bounce: convert multipage bvecs into singlepage Date: Tue, 27 Dec 2016 23:56:11 +0800 Message-Id: <1482854250-13481-23-git-send-email-tom.leiming@gmail.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1482854250-13481-1-git-send-email-tom.leiming@gmail.com> References: <1482854250-13481-1-git-send-email-tom.leiming@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch trys to split the incoming multipage bvecs bio, so that the splitted bio can be held into one singlepage bvecs bio. Signed-off-by: Ming Lei --- block/bounce.c | 41 +++++++++++++++++++++++++++++++++-------- 1 file changed, 33 insertions(+), 8 deletions(-) diff --git a/block/bounce.c b/block/bounce.c index a42f7b98b7e6..08841ed4cdae 100644 --- a/block/bounce.c +++ b/block/bounce.c @@ -187,22 +187,33 @@ static void bounce_end_io_read_isa(struct bio *bio) __bounce_end_io_read(bio, isa_page_pool); } +static inline bool need_bounce(struct request_queue *q, struct bio *bio) +{ + struct bvec_iter iter; + struct bio_vec bv; + + bio_for_each_segment_mp(bv, bio, iter) { + unsigned nr = (bv.bv_offset + bv.bv_len - 1) >> + PAGE_SHIFT; + + if (page_to_pfn(bv.bv_page) + nr > queue_bounce_pfn(q)) + return true; + } + return false; +} + static void __blk_queue_bounce(struct request_queue *q, struct bio **bio_orig, mempool_t *pool) { struct bio *bio; int rw = bio_data_dir(*bio_orig); - struct bio_vec *to, from; - struct bvec_iter iter; + struct bio_vec *to; unsigned i; - bio_for_each_segment(from, *bio_orig, iter) - if (page_to_pfn(from.bv_page) > queue_bounce_pfn(q)) - goto bounce; + if (!need_bounce(q, *bio_orig)) + return; - return; -bounce: - bio = bio_clone_bioset(*bio_orig, GFP_NOIO, fs_bio_set); + bio = bio_clone_bioset_sp(*bio_orig, GFP_NOIO, fs_bio_set); bio_for_each_segment_all(to, bio, i) { struct page *page = to->bv_page; @@ -246,6 +257,7 @@ static void __blk_queue_bounce(struct request_queue *q, struct bio **bio_orig, void blk_queue_bounce(struct request_queue *q, struct bio **bio_orig) { mempool_t *pool; + unsigned sectors; /* * Data-less bio, nothing to bounce @@ -267,9 +279,22 @@ void blk_queue_bounce(struct request_queue *q, struct bio **bio_orig) pool = isa_page_pool; } + if (!need_bounce(q, *bio_orig)) + return; + /* * slow path + * + * REQ_PC bio won't reach splitting because multipage bvec + * isn't enabled for REQ_PC. */ + if (!bio_can_convert_to_sp(*bio_orig, §ors)) { + struct bio *split = bio_split(*bio_orig, sectors, + GFP_NOIO, q->bio_split); + bio_chain(split, *bio_orig); + generic_make_request(*bio_orig); + *bio_orig = split; + } __blk_queue_bounce(q, bio_orig, pool); } -- 2.7.4