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| author | Jaegeuk Kim <jaegeuk.kim@samsung.com> | 2013-04-29 11:58:39 +0400 |
|---|---|---|
| committer | Jaegeuk Kim <jaegeuk.kim@samsung.com> | 2013-04-30 07:07:32 +0400 |
| commit | ac5d156c78a68b39955ee9b09498ba93831c77d7 (patch) | |
| tree | 638245b8a39332d3bb2878c5a0a8574e518fcc37 /fs | |
| parent | b743ba78ae4c7c6a6e08e623af824b6208f58019 (diff) | |
| download | linux-ac5d156c78a68b39955ee9b09498ba93831c77d7.tar.xz | |
f2fs: modify the number of issued pages to merge IOs
When testing f2fs on an SSD, I found some 128 page IOs followed by 1 page IO
were issued by f2fs_write_node_pages.
This means that there were some mishandling flows which degrades performance.
Previous f2fs_write_node_pages determines the number of pages to be written,
nr_to_write, as follows.
1. The bio_get_nr_vecs returns 129 pages.
2. The bio_alloc makes a room for 128 pages.
3. The initial 128 pages go into one bio.
4. The existing bio is submitted, and a new bio is prepared for the last 1 page.
5. Finally, sync_node_pages submits the last 1 page bio.
The problem is from the use of bio_get_nr_vecs, so this patch replace it
with max_hw_blocks using queue_max_sectors.
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/f2fs/node.c | 6 | ||||
| -rw-r--r-- | fs/f2fs/segment.c | 2 | ||||
| -rw-r--r-- | fs/f2fs/segment.h | 11 |
3 files changed, 14 insertions, 5 deletions
diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c index f14eb7b8b2c4..7209d637f942 100644 --- a/fs/f2fs/node.c +++ b/fs/f2fs/node.c @@ -1171,7 +1171,6 @@ static int f2fs_write_node_pages(struct address_space *mapping, struct writeback_control *wbc) { struct f2fs_sb_info *sbi = F2FS_SB(mapping->host->i_sb); - struct block_device *bdev = sbi->sb->s_bdev; long nr_to_write = wbc->nr_to_write; /* First check balancing cached NAT entries */ @@ -1185,10 +1184,9 @@ static int f2fs_write_node_pages(struct address_space *mapping, return 0; /* if mounting is failed, skip writing node pages */ - wbc->nr_to_write = bio_get_nr_vecs(bdev); + wbc->nr_to_write = max_hw_blocks(sbi); sync_node_pages(sbi, 0, wbc); - wbc->nr_to_write = nr_to_write - - (bio_get_nr_vecs(bdev) - wbc->nr_to_write); + wbc->nr_to_write = nr_to_write - (max_hw_blocks(sbi) - wbc->nr_to_write); return 0; } diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c index 392ccb3d10b9..d8e84e49a5c3 100644 --- a/fs/f2fs/segment.c +++ b/fs/f2fs/segment.c @@ -734,7 +734,7 @@ static void submit_write_page(struct f2fs_sb_info *sbi, struct page *page, do_submit_bio(sbi, type, false); alloc_new: if (sbi->bio[type] == NULL) { - sbi->bio[type] = f2fs_bio_alloc(bdev, bio_get_nr_vecs(bdev)); + sbi->bio[type] = f2fs_bio_alloc(bdev, max_hw_blocks(sbi)); sbi->bio[type]->bi_sector = SECTOR_FROM_BLOCK(sbi, blk_addr); /* * The end_io will be assigned at the sumbission phase. diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h index 26fc0540f144..062424a0e4c3 100644 --- a/fs/f2fs/segment.h +++ b/fs/f2fs/segment.h @@ -8,6 +8,8 @@ * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ +#include <linux/blkdev.h> + /* constant macro */ #define NULL_SEGNO ((unsigned int)(~0)) #define NULL_SECNO ((unsigned int)(~0)) @@ -86,6 +88,8 @@ #define SECTOR_FROM_BLOCK(sbi, blk_addr) \ (blk_addr << ((sbi)->log_blocksize - F2FS_LOG_SECTOR_SIZE)) +#define SECTOR_TO_BLOCK(sbi, sectors) \ + (sectors >> ((sbi)->log_blocksize - F2FS_LOG_SECTOR_SIZE)) /* during checkpoint, bio_private is used to synchronize the last bio */ struct bio_private { @@ -624,3 +628,10 @@ static inline bool sec_usage_check(struct f2fs_sb_info *sbi, unsigned int secno) return true; return false; } + +static inline unsigned int max_hw_blocks(struct f2fs_sb_info *sbi) +{ + struct block_device *bdev = sbi->sb->s_bdev; + struct request_queue *q = bdev_get_queue(bdev); + return SECTOR_TO_BLOCK(sbi, queue_max_sectors(q)); +} |