f2fs: avoid small data writes by skipping writepages

This patch introduces nr_pages_to_skip(sbi, type) to determine writepages can
be skipped.
The dentry, node, and meta pages can be conrolled by F2FS without breaking the
FS consistency.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
This commit is contained in:
Jaegeuk Kim 2014-03-18 12:40:49 +09:00
parent f8b2c1f940
commit 87d6f89094
4 changed files with 26 additions and 9 deletions

View File

@ -187,7 +187,7 @@ static int f2fs_write_meta_pages(struct address_space *mapping,
struct writeback_control *wbc)
{
struct f2fs_sb_info *sbi = F2FS_SB(mapping->host->i_sb);
int nrpages = MAX_BIO_BLOCKS(max_hw_blocks(sbi));
int nrpages = nr_pages_to_skip(sbi, META);
long written;
if (wbc->for_kupdate)
@ -682,7 +682,7 @@ retry:
inode = igrab(entry->inode);
spin_unlock(&sbi->dir_inode_lock);
if (inode) {
filemap_flush(inode->i_mapping);
filemap_fdatawrite(inode->i_mapping);
iput(inode);
} else {
/*

View File

@ -868,6 +868,10 @@ static int f2fs_write_data_pages(struct address_space *mapping,
if (!mapping->a_ops->writepage)
return 0;
if (S_ISDIR(inode->i_mode) && wbc->sync_mode == WB_SYNC_NONE &&
get_dirty_dents(inode) < nr_pages_to_skip(sbi, DATA))
return 0;
if (wbc->nr_to_write < MAX_DESIRED_PAGES_WP) {
desired_nrtw = MAX_DESIRED_PAGES_WP;
excess_nrtw = desired_nrtw - wbc->nr_to_write;

View File

@ -1198,12 +1198,6 @@ redirty_out:
return AOP_WRITEPAGE_ACTIVATE;
}
/*
* It is very important to gather dirty pages and write at once, so that we can
* submit a big bio without interfering other data writes.
* Be default, 512 pages (2MB) * 3 node types, is more reasonable.
*/
#define COLLECT_DIRTY_NODES 1536
static int f2fs_write_node_pages(struct address_space *mapping,
struct writeback_control *wbc)
{
@ -1214,7 +1208,7 @@ static int f2fs_write_node_pages(struct address_space *mapping,
f2fs_balance_fs_bg(sbi);
/* collect a number of dirty node pages and write together */
if (get_pages(sbi, F2FS_DIRTY_NODES) < COLLECT_DIRTY_NODES)
if (get_pages(sbi, F2FS_DIRTY_NODES) < nr_pages_to_skip(sbi, NODE))
return 0;
/* if mounting is failed, skip writing node pages */

View File

@ -664,3 +664,22 @@ static inline unsigned int max_hw_blocks(struct f2fs_sb_info *sbi)
struct request_queue *q = bdev_get_queue(bdev);
return SECTOR_TO_BLOCK(sbi, queue_max_sectors(q));
}
/*
* It is very important to gather dirty pages and write at once, so that we can
* submit a big bio without interfering other data writes.
* By default, 512 pages for directory data,
* 512 pages (2MB) * 3 for three types of nodes, and
* max_bio_blocks for meta are set.
*/
static inline int nr_pages_to_skip(struct f2fs_sb_info *sbi, int type)
{
if (type == DATA)
return sbi->blocks_per_seg;
else if (type == NODE)
return 3 * sbi->blocks_per_seg;
else if (type == META)
return MAX_BIO_BLOCKS(max_hw_blocks(sbi));
else
return 0;
}