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| author | Jaegeuk Kim <jaegeuk.kim@samsung.com> | 2013-04-24 13:19:56 +0900 |
|---|---|---|
| committer | Jaegeuk Kim <jaegeuk.kim@samsung.com> | 2013-04-26 10:35:10 +0900 |
| commit | c718379b6b0954a04a153d7e5dc8b3136a301ee6 (patch) | |
| tree | eca5d2d44291de009acb51ebc934f70de6d0ffa7 /fs/f2fs/node.c | |
| parent | 6cb968d9b0358c7e807416a85699a526e820083c (diff) | |
| download | lwn-c718379b6b0954a04a153d7e5dc8b3136a301ee6.tar.gz lwn-c718379b6b0954a04a153d7e5dc8b3136a301ee6.zip | |
f2fs: give a chance to merge IOs by IO scheduler
Previously, background GC submits many 4KB read requests to load victim blocks
and/or its (i)node blocks.
...
f2fs_gc : f2fs_readpage: ino = 1, page_index = 0xb61, blkaddr = 0x3b964ed
f2fs_gc : block_rq_complete: 8,16 R () 499854968 + 8 [0]
f2fs_gc : f2fs_readpage: ino = 1, page_index = 0xb6f, blkaddr = 0x3b964ee
f2fs_gc : block_rq_complete: 8,16 R () 499854976 + 8 [0]
f2fs_gc : f2fs_readpage: ino = 1, page_index = 0xb79, blkaddr = 0x3b964ef
f2fs_gc : block_rq_complete: 8,16 R () 499854984 + 8 [0]
...
However, by the fact that many IOs are sequential, we can give a chance to merge
the IOs by IO scheduler.
In order to do that, let's use blk_plug.
...
f2fs_gc : f2fs_iget: ino = 143
f2fs_gc : f2fs_readpage: ino = 143, page_index = 0x1c6, blkaddr = 0x2e6ee
f2fs_gc : f2fs_iget: ino = 143
f2fs_gc : f2fs_readpage: ino = 143, page_index = 0x1c7, blkaddr = 0x2e6ef
<idle> : block_rq_complete: 8,16 R () 1519616 + 8 [0]
<idle> : block_rq_complete: 8,16 R () 1519848 + 8 [0]
<idle> : block_rq_complete: 8,16 R () 1520432 + 96 [0]
<idle> : block_rq_complete: 8,16 R () 1520536 + 104 [0]
<idle> : block_rq_complete: 8,16 R () 1521008 + 112 [0]
<idle> : block_rq_complete: 8,16 R () 1521440 + 152 [0]
<idle> : block_rq_complete: 8,16 R () 1521688 + 144 [0]
<idle> : block_rq_complete: 8,16 R () 1522128 + 192 [0]
<idle> : block_rq_complete: 8,16 R () 1523256 + 328 [0]
...
Note that this issue should be addressed in checkpoint, and some readahead
flows too.
Reviewed-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Diffstat (limited to 'fs/f2fs/node.c')
| -rw-r--r-- | fs/f2fs/node.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c index 5a825502b0b0..a0aa0446a237 100644 --- a/fs/f2fs/node.c +++ b/fs/f2fs/node.c @@ -89,10 +89,13 @@ 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; @@ -110,6 +113,7 @@ static void ra_nat_pages(struct f2fs_sb_info *sbi, int nid) f2fs_put_page(page, 0); } + blk_finish_plug(&plug); } static struct nat_entry *__lookup_nat_cache(struct f2fs_nm_info *nm_i, nid_t n) @@ -942,6 +946,7 @@ struct page *get_node_page_ra(struct page *parent, int start) { struct f2fs_sb_info *sbi = F2FS_SB(parent->mapping->host->i_sb); struct address_space *mapping = sbi->node_inode->i_mapping; + struct blk_plug plug; struct page *page; int err, i, end; nid_t nid; @@ -961,6 +966,8 @@ struct page *get_node_page_ra(struct page *parent, int start) else if (err == LOCKED_PAGE) goto page_hit; + blk_start_plug(&plug); + /* Then, try readahead for siblings of the desired node */ end = start + MAX_RA_NODE; end = min(end, NIDS_PER_BLOCK); @@ -971,6 +978,8 @@ struct page *get_node_page_ra(struct page *parent, int start) ra_node_page(sbi, nid); } + blk_finish_plug(&plug); + lock_page(page); page_hit: |