From mboxrd@z Thu Jan 1 00:00:00 1970 From: NeilBrown Subject: [md PATCH 03/34] md/raid10: share pages between read and write bio's during recovery Date: Thu, 21 Jul 2011 12:32:24 +1000 Message-ID: <20110721023224.6728.96829.stgit@notabene.brown> References: <20110721022537.6728.90204.stgit@notabene.brown> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20110721022537.6728.90204.stgit@notabene.brown> Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org Cc: Namhyung Kim List-Id: linux-raid.ids From: Namhyung Kim When performing a recovery, only first 2 slots in r10_bio are in use, for read and write respectively. However all of pages in the write bio are never used and just replaced to read bio's when the read completes. Get rid of those unused pages and share read pages properly. Signed-off-by: Namhyung Kim Signed-off-by: NeilBrown --- drivers/md/raid10.c | 23 ++++++++++++----------- 1 files changed, 12 insertions(+), 11 deletions(-) diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c index e434f1e..3715e22 100644 --- a/drivers/md/raid10.c +++ b/drivers/md/raid10.c @@ -123,7 +123,14 @@ static void * r10buf_pool_alloc(gfp_t gfp_flags, void *data) for (j = 0 ; j < nalloc; j++) { bio = r10_bio->devs[j].bio; for (i = 0; i < RESYNC_PAGES; i++) { - page = alloc_page(gfp_flags); + if (j == 1 && !test_bit(MD_RECOVERY_SYNC, + &conf->mddev->recovery)) { + /* we can share bv_page's during recovery */ + struct bio *rbio = r10_bio->devs[0].bio; + page = rbio->bi_io_vec[i].bv_page; + get_page(page); + } else + page = alloc_page(gfp_flags); if (unlikely(!page)) goto out_free_pages; @@ -1360,20 +1367,14 @@ done: static void recovery_request_write(mddev_t *mddev, r10bio_t *r10_bio) { conf_t *conf = mddev->private; - int i, d; - struct bio *bio, *wbio; - + int d; + struct bio *wbio; - /* move the pages across to the second bio + /* + * share the pages with the first bio * and submit the write request */ - bio = r10_bio->devs[0].bio; wbio = r10_bio->devs[1].bio; - for (i=0; i < wbio->bi_vcnt; i++) { - struct page *p = bio->bi_io_vec[i].bv_page; - bio->bi_io_vec[i].bv_page = wbio->bi_io_vec[i].bv_page; - wbio->bi_io_vec[i].bv_page = p; - } d = r10_bio->devs[1].devnum; atomic_inc(&conf->mirrors[d].rdev->nr_pending);