f2fs: read node blocks ahead when truncating blocks

This patch enables reading node blocks in advance when truncating large
data blocks.

 > time rm $MNT/testfile (500GB) after drop_cachees
Before : 9.422 s
After  : 4.821 s

Reported-by: Stephen Bates <stephen.bates@microsemi.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
This commit is contained in:
Jaegeuk Kim 2016-05-06 16:19:43 -07:00
parent e12dd7bd87
commit 79344efb93
2 changed files with 29 additions and 25 deletions

View File

@ -584,7 +584,7 @@ int truncate_blocks(struct inode *inode, u64 from, bool lock)
}
set_new_dnode(&dn, inode, ipage, NULL, 0);
err = get_dnode_of_data(&dn, free_from, LOOKUP_NODE);
err = get_dnode_of_data(&dn, free_from, LOOKUP_NODE_RA);
if (err) {
if (err == -ENOENT)
goto free_next;

View File

@ -407,6 +407,29 @@ cache:
up_write(&nm_i->nat_tree_lock);
}
/*
* readahead MAX_RA_NODE number of node pages.
*/
static void ra_node_pages(struct page *parent, int start, int n)
{
struct f2fs_sb_info *sbi = F2FS_P_SB(parent);
struct blk_plug plug;
int i, end;
nid_t nid;
blk_start_plug(&plug);
/* Then, try readahead for siblings of the desired node */
end = start + n;
end = min(end, NIDS_PER_BLOCK);
for (i = start; i < end; i++) {
nid = get_nid(parent, i, false);
ra_node_page(sbi, nid);
}
blk_finish_plug(&plug);
}
pgoff_t get_next_page_offset(struct dnode_of_data *dn, pgoff_t pgofs)
{
const long direct_index = ADDRS_PER_INODE(dn->inode);
@ -707,6 +730,8 @@ static int truncate_nodes(struct dnode_of_data *dn, unsigned int nofs,
return PTR_ERR(page);
}
ra_node_pages(page, ofs, NIDS_PER_BLOCK);
rn = F2FS_NODE(page);
if (depth < 3) {
for (i = ofs; i < NIDS_PER_BLOCK; i++, freed++) {
@ -784,6 +809,8 @@ static int truncate_partial_nodes(struct dnode_of_data *dn,
nid[i + 1] = get_nid(pages[i], offset[i + 1], false);
}
ra_node_pages(pages[idx], offset[idx + 1], NIDS_PER_BLOCK);
/* free direct nodes linked to a partial indirect node */
for (i = offset[idx + 1]; i < NIDS_PER_BLOCK; i++) {
child_nid = get_nid(pages[idx], i, false);
@ -1095,29 +1122,6 @@ void ra_node_page(struct f2fs_sb_info *sbi, nid_t nid)
f2fs_put_page(apage, err ? 1 : 0);
}
/*
* readahead MAX_RA_NODE number of node pages.
*/
static void ra_node_pages(struct page *parent, int start)
{
struct f2fs_sb_info *sbi = F2FS_P_SB(parent);
struct blk_plug plug;
int i, end;
nid_t nid;
blk_start_plug(&plug);
/* Then, try readahead for siblings of the desired node */
end = start + MAX_RA_NODE;
end = min(end, NIDS_PER_BLOCK);
for (i = start; i < end; i++) {
nid = get_nid(parent, i, false);
ra_node_page(sbi, nid);
}
blk_finish_plug(&plug);
}
static struct page *__get_node_page(struct f2fs_sb_info *sbi, pgoff_t nid,
struct page *parent, int start)
{
@ -1141,7 +1145,7 @@ repeat:
}
if (parent)
ra_node_pages(parent, start + 1);
ra_node_pages(parent, start + 1, MAX_RA_NODE);
lock_page(page);