From 1dcc336b02bff3d38f173feac55a2b6c25a5fb54 Mon Sep 17 00:00:00 2001 From: Chao Yu Date: Thu, 5 Feb 2015 17:57:31 +0800 Subject: [PATCH] f2fs: enable rb-tree extent cache This patch enables rb-tree based extent cache in f2fs. When we mount with "-o extent_cache", f2fs will try to add recently accessed page-block mappings into rb-tree based extent cache as much as possible, instead of original one extent info cache. By this way, f2fs can support more effective cache between dnode page cache and disk. It will supply high hit ratio in the cache with fewer memory when dnode page cache are reclaimed in environment of low memory. Storage: Sandisk sd card 64g 1.append write file (offset: 0, size: 128M); 2.override write file (offset: 2M, size: 1M); 3.override write file (offset: 4M, size: 1M); ... 4.override write file (offset: 48M, size: 1M); ... 5.override write file (offset: 112M, size: 1M); 6.sync 7.echo 3 > /proc/sys/vm/drop_caches 8.read file (size:128M, unit: 4k, count: 32768) (time dd if=/mnt/f2fs/128m bs=4k count=32768) Extent Hit Ratio: before patched Hit Ratio 121 / 1071 1071 / 1071 Performance: before patched real 0m37.051s 0m35.556s user 0m0.040s 0m0.026s sys 0m2.990s 0m2.251s Memory Cost: before patched Tree Count: 0 1 (size: 24 bytes) Node Count: 0 45 (size: 1440 bytes) v3: o retest and given more details of test result. Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim --- fs/f2fs/data.c | 13 +++++++++++++ fs/f2fs/inode.c | 1 + fs/f2fs/segment.c | 3 +++ fs/f2fs/super.c | 9 ++++++++- 4 files changed, 25 insertions(+), 1 deletion(-) diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index f527453..acdc076 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -666,6 +666,9 @@ void f2fs_shrink_extent_tree(struct f2fs_sb_info *sbi, int nr_shrink) void **slot; unsigned int found; + if (!test_opt(sbi, EXTENT_CACHE)) + return; + if (available_free_memory(sbi, EXTENT_CACHE)) return; @@ -714,6 +717,9 @@ void f2fs_destroy_extent_tree(struct inode *inode) struct f2fs_sb_info *sbi = F2FS_I_SB(inode); struct extent_tree *et; + if (!test_opt(sbi, EXTENT_CACHE)) + return; + down_read(&sbi->extent_tree_lock); et = radix_tree_lookup(&sbi->extent_tree_root, inode->i_ino); if (!et) { @@ -749,6 +755,9 @@ out: static bool f2fs_lookup_extent_cache(struct inode *inode, pgoff_t pgofs, struct extent_info *ei) { + if (test_opt(F2FS_I_SB(inode), EXTENT_CACHE)) + return f2fs_lookup_extent_tree(inode, pgofs, ei); + return lookup_extent_info(inode, pgofs, ei); } @@ -765,6 +774,10 @@ void f2fs_update_extent_cache(struct dnode_of_data *dn) fofs = start_bidx_of_node(ofs_of_node(dn->node_page), fi) + dn->ofs_in_node; + if (test_opt(F2FS_I_SB(dn->inode), EXTENT_CACHE)) + return f2fs_update_extent_tree(dn->inode, fofs, + dn->data_blkaddr); + if (update_extent_info(dn->inode, fofs, dn->data_blkaddr)) sync_inode_page(dn); } diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c index 28dd26a..b508744 100644 --- a/fs/f2fs/inode.c +++ b/fs/f2fs/inode.c @@ -335,6 +335,7 @@ void f2fs_evict_inode(struct inode *inode) no_delete: stat_dec_inline_dir(inode); stat_dec_inline_inode(inode); + f2fs_destroy_extent_tree(inode); invalidate_mapping_pages(NODE_MAPPING(sbi), inode->i_ino, inode->i_ino); if (xnid) invalidate_mapping_pages(NODE_MAPPING(sbi), xnid, xnid); diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c index daee4ab..29c04ed 100644 --- a/fs/f2fs/segment.c +++ b/fs/f2fs/segment.c @@ -277,6 +277,9 @@ void f2fs_balance_fs(struct f2fs_sb_info *sbi) void f2fs_balance_fs_bg(struct f2fs_sb_info *sbi) { + /* try to shrink extent cache when there is no enough memory */ + f2fs_shrink_extent_tree(sbi, EXTENT_CACHE_SHRINK_NUMBER); + /* check the # of cached NAT entries and prefree segments */ if (try_to_free_nats(sbi, NAT_ENTRY_PER_BLOCK) || excess_prefree_segs(sbi) || diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c index 3ce4d7c..e649f21 100644 --- a/fs/f2fs/super.c +++ b/fs/f2fs/super.c @@ -1079,6 +1079,8 @@ try_onemore: INIT_LIST_HEAD(&sbi->dir_inode_list); spin_lock_init(&sbi->dir_inode_lock); + init_extent_cache_info(sbi); + init_ino_entry_info(sbi); /* setup f2fs internal modules */ @@ -1285,10 +1287,13 @@ static int __init init_f2fs_fs(void) err = create_checkpoint_caches(); if (err) goto free_segment_manager_caches; + err = create_extent_cache(); + if (err) + goto free_checkpoint_caches; f2fs_kset = kset_create_and_add("f2fs", NULL, fs_kobj); if (!f2fs_kset) { err = -ENOMEM; - goto free_checkpoint_caches; + goto free_extent_cache; } err = register_filesystem(&f2fs_fs_type); if (err) @@ -1299,6 +1304,8 @@ static int __init init_f2fs_fs(void) free_kset: kset_unregister(f2fs_kset); +free_extent_cache: + destroy_extent_cache(); free_checkpoint_caches: destroy_checkpoint_caches(); free_segment_manager_caches: -- 2.7.4