[PATCH] f2fs: merge read IOs at ra_nat_pages()

From: Jaegeuk Kim
Date: Thu Nov 21 2013 - 04:37:03 EST


This patch changes the policy of submitting read bios at ra_nat_pages.

Previously, f2fs submits small read bios with block plugging.
But, with this patch, f2fs itself merges read bios first and then submits a
large bio, which can reduce the bio handling overheads.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@xxxxxxxxxxx>
---
fs/f2fs/node.c | 8 ++------
1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index b843a5b..c06871f 100644
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -89,13 +89,10 @@ static void ra_nat_pages(struct f2fs_sb_info *sbi, int nid)
{
struct address_space *mapping = sbi->meta_inode->i_mapping;
struct f2fs_nm_info *nm_i = NM_I(sbi);
- struct blk_plug plug;
struct page *page;
pgoff_t index;
int i;

- blk_start_plug(&plug);
-
for (i = 0; i < FREE_NID_PAGES; i++, nid += NAT_ENTRY_PER_BLOCK) {
if (nid >= nm_i->max_nid)
nid = 0;
@@ -108,12 +105,11 @@ static void ra_nat_pages(struct f2fs_sb_info *sbi, int nid)
f2fs_put_page(page, 1);
continue;
}
- if (f2fs_readpage(sbi, page, index, READ))
- continue;
+ submit_read_page(sbi, page, index, READ_SYNC);

f2fs_put_page(page, 0);
}
- blk_finish_plug(&plug);
+ f2fs_submit_read_bio(sbi, READ_SYNC);
}

static struct nat_entry *__lookup_nat_cache(struct f2fs_nm_info *nm_i, nid_t n)
--
1.8.4.474.g128a96c

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