Commit 7ea984b0 authored Aug 27, 2016 by Chao Yu Committed by Jaegeuk Kim Sep 07, 2016

f2fs: do in batch synchronously readahead during GC

In order to enhance performance, we try to readahead node page during
GC, but before loading node page we should get block address of node page
which is stored in NAT table, so synchronously read of single NAT page
block our readahead flow.

f2fs_submit_page_bio: dev = (251,0), ino = 2, page_index = 0xa1e, oldaddr = 0xa1e, newaddr = 0xa1e, rw = READ_SYNC(MP), type = META
f2fs_submit_page_bio: dev = (251,0), ino = 1, page_index = 0x35e9, oldaddr = 0x72d7a, newaddr = 0x72d7a, rw = READAHEAD ^H, type = NODE
f2fs_submit_page_bio: dev = (251,0), ino = 2, page_index = 0xc1f, oldaddr = 0xc1f, newaddr = 0xc1f, rw = READ_SYNC(MP), type = META
f2fs_submit_page_bio: dev = (251,0), ino = 1, page_index = 0x389d, oldaddr = 0x72d7d, newaddr = 0x72d7d, rw = READAHEAD ^H, type = NODE
f2fs_submit_page_bio: dev = (251,0), ino = 1, page_index = 0x3a82, oldaddr = 0x72d7f, newaddr = 0x72d7f, rw = READAHEAD ^H, type = NODE
f2fs_submit_page_bio: dev = (251,0), ino = 1, page_index = 0x3bfa, oldaddr = 0x72d86, newaddr = 0x72d86, rw = READAHEAD ^H, type = NODE

This patch adds one phase that do readahead NAT pages in batch before
readahead node page for more effeciently.

f2fs_submit_page_bio: dev = (251,0), ino = 2, page_index = 0x1952, oldaddr = 0x1952, newaddr = 0x1952, rw = READ_SYNC(MP), type = META
f2fs_submit_page_mbio: dev = (251,0), ino = 2, page_index = 0xc34, oldaddr = 0xc34, newaddr = 0xc34, rw = READ_SYNC(MP), type = META
f2fs_submit_page_mbio: dev = (251,0), ino = 2, page_index = 0xa33, oldaddr = 0xa33, newaddr = 0xa33, rw = READ_SYNC(MP), type = META
f2fs_submit_page_mbio: dev = (251,0), ino = 2, page_index = 0xc30, oldaddr = 0xc30, newaddr = 0xc30, rw = READ_SYNC(MP), type = META
f2fs_submit_page_mbio: dev = (251,0), ino = 2, page_index = 0xc32, oldaddr = 0xc32, newaddr = 0xc32, rw = READ_SYNC(MP), type = META
f2fs_submit_page_mbio: dev = (251,0), ino = 2, page_index = 0xc26, oldaddr = 0xc26, newaddr = 0xc26, rw = READ_SYNC(MP), type = META
f2fs_submit_page_mbio: dev = (251,0), ino = 2, page_index = 0xa2b, oldaddr = 0xa2b, newaddr = 0xa2b, rw = READ_SYNC(MP), type = META
f2fs_submit_page_mbio: dev = (251,0), ino = 2, page_index = 0xc23, oldaddr = 0xc23, newaddr = 0xc23, rw = READ_SYNC(MP), type = META
f2fs_submit_page_mbio: dev = (251,0), ino = 2, page_index = 0xc24, oldaddr = 0xc24, newaddr = 0xc24, rw = READ_SYNC(MP), type = META
f2fs_submit_page_mbio: dev = (251,0), ino = 2, page_index = 0xa10, oldaddr = 0xa10, newaddr = 0xa10, rw = READ_SYNC(MP), type = META
f2fs_submit_page_mbio: dev = (251,0), ino = 2, page_index = 0xc2c, oldaddr = 0xc2c, newaddr = 0xc2c, rw = READ_SYNC(MP), type = META
f2fs_submit_page_bio: dev = (251,0), ino = 1, page_index = 0x5db7, oldaddr = 0x6be00, newaddr = 0x6be00, rw = READAHEAD ^H, type = NODE
f2fs_submit_page_bio: dev = (251,0), ino = 1, page_index = 0x5db9, oldaddr = 0x6be17, newaddr = 0x6be17, rw = READAHEAD ^H, type = NODE
f2fs_submit_page_bio: dev = (251,0), ino = 1, page_index = 0x5dbc, oldaddr = 0x6be1a, newaddr = 0x6be1a, rw = READAHEAD ^H, type = NODE
f2fs_submit_page_bio: dev = (251,0), ino = 1, page_index = 0x5dc3, oldaddr = 0x6be20, newaddr = 0x6be20, rw = READAHEAD ^H, type = NODE
f2fs_submit_page_bio: dev = (251,0), ino = 1, page_index = 0x5dc7, oldaddr = 0x6be24, newaddr = 0x6be24, rw = READAHEAD ^H, type = NODE
f2fs_submit_page_bio: dev = (251,0), ino = 1, page_index = 0x5dc9, oldaddr = 0x6be25, newaddr = 0x6be25, rw = READAHEAD ^H, type = NODE

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

parent 74fa5f3d

fs/f2fs/gc.c

+23 −10

Original line number	Diff line number	Diff line
		@@ -423,10 +423,10 @@ static int check_valid_map(struct f2fs_sb_info *sbi,
		static void gc_node_segment(struct f2fs_sb_info *sbi,
		struct f2fs_summary *sum, unsigned int segno, int gc_type)
		{
		bool initial = true;
		struct f2fs_summary *entry;
		block_t start_addr;
		int off;
		int phase = 0;

		start_addr = START_BLOCK(sbi, segno);

		@@ -445,10 +445,18 @@ static void gc_node_segment(struct f2fs_sb_info *sbi,
		if (check_valid_map(sbi, segno, off) == 0)
		continue;

		if (initial) {
		if (phase == 0) {
		ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), 1,
		META_NAT, true);
		continue;
		}

		if (phase == 1) {
		ra_node_page(sbi, nid);
		continue;
		}

		/* phase == 2 */
		node_page = get_node_page(sbi, nid);
		if (IS_ERR(node_page))
		continue;
		@@ -469,11 +477,9 @@ static void gc_node_segment(struct f2fs_sb_info *sbi,
		stat_inc_node_blk_count(sbi, 1, gc_type);
		}

		if (initial) {
		initial = false;
		if (++phase < 3)
		goto next_step;
		}
		}

		/*
		* Calculate start block index indicating the given node offset.
		@@ -706,6 +712,7 @@ static void gc_data_segment(struct f2fs_sb_info sbi, struct f2fs_summary sum,
		struct node_info dni; /* dnode info for the data */
		unsigned int ofs_in_node, nofs;
		block_t start_bidx;
		nid_t nid = le32_to_cpu(entry->nid);

		/* stop BG_GC if there is not enough free sections. */
		if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0))
		@@ -715,7 +722,13 @@ static void gc_data_segment(struct f2fs_sb_info sbi, struct f2fs_summary sum,
		continue;

		if (phase == 0) {
		ra_node_page(sbi, le32_to_cpu(entry->nid));
		ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), 1,
		META_NAT, true);
		continue;
		}

		if (phase == 1) {
		ra_node_page(sbi, nid);
		continue;
		}

		@@ -723,14 +736,14 @@ static void gc_data_segment(struct f2fs_sb_info sbi, struct f2fs_summary sum,
		if (!is_alive(sbi, entry, &dni, start_addr + off, &nofs))
		continue;

		if (phase == 1) {
		if (phase == 2) {
		ra_node_page(sbi, dni.ino);
		continue;
		}

		ofs_in_node = le16_to_cpu(entry->ofs_in_node);

		if (phase == 2) {
		if (phase == 3) {
		inode = f2fs_iget(sb, dni.ino);
		if (IS_ERR(inode) \|\| is_bad_inode(inode))
		continue;
		@@ -756,7 +769,7 @@ static void gc_data_segment(struct f2fs_sb_info sbi, struct f2fs_summary sum,
		continue;
		}

		/* phase 3 */
		/* phase 4 */
		inode = find_gc_inode(gc_list, dni.ino);
		if (inode) {
		struct f2fs_inode_info *fi = F2FS_I(inode);
		@@ -789,7 +802,7 @@ static void gc_data_segment(struct f2fs_sb_info sbi, struct f2fs_summary sum,
		}
		}

		if (++phase < 4)
		if (++phase < 5)
		goto next_step;
		}