From c65060ad4274f70048d62e0a86332cd3fd23f28d Mon Sep 17 00:00:00 2001 From: Namhyung Kim Date: Mon, 18 Jul 2011 17:38:49 +1000 Subject: [PATCH] md/raid10: share pages between read and write bio's during recovery 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 file changed, 12 insertions(+), 11 deletions(-) diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c index e434f1e8d223..3715e220e5e0 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);