From: Jaegeuk Kim Date: Wed, 24 Apr 2013 04:19:56 +0000 (+0900) Subject: f2fs: give a chance to merge IOs by IO scheduler X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=c718379b6b0954a04a153d7e5dc8b3136a301ee6;p=openwrt%2Fstaging%2Fblogic.git f2fs: give a chance to merge IOs by IO scheduler Previously, background GC submits many 4KB read requests to load victim blocks and/or its (i)node blocks. ... f2fs_gc : f2fs_readpage: ino = 1, page_index = 0xb61, blkaddr = 0x3b964ed f2fs_gc : block_rq_complete: 8,16 R () 499854968 + 8 [0] f2fs_gc : f2fs_readpage: ino = 1, page_index = 0xb6f, blkaddr = 0x3b964ee f2fs_gc : block_rq_complete: 8,16 R () 499854976 + 8 [0] f2fs_gc : f2fs_readpage: ino = 1, page_index = 0xb79, blkaddr = 0x3b964ef f2fs_gc : block_rq_complete: 8,16 R () 499854984 + 8 [0] ... However, by the fact that many IOs are sequential, we can give a chance to merge the IOs by IO scheduler. In order to do that, let's use blk_plug. ... f2fs_gc : f2fs_iget: ino = 143 f2fs_gc : f2fs_readpage: ino = 143, page_index = 0x1c6, blkaddr = 0x2e6ee f2fs_gc : f2fs_iget: ino = 143 f2fs_gc : f2fs_readpage: ino = 143, page_index = 0x1c7, blkaddr = 0x2e6ef : block_rq_complete: 8,16 R () 1519616 + 8 [0] : block_rq_complete: 8,16 R () 1519848 + 8 [0] : block_rq_complete: 8,16 R () 1520432 + 96 [0] : block_rq_complete: 8,16 R () 1520536 + 104 [0] : block_rq_complete: 8,16 R () 1521008 + 112 [0] : block_rq_complete: 8,16 R () 1521440 + 152 [0] : block_rq_complete: 8,16 R () 1521688 + 144 [0] : block_rq_complete: 8,16 R () 1522128 + 192 [0] : block_rq_complete: 8,16 R () 1523256 + 328 [0] ... Note that this issue should be addressed in checkpoint, and some readahead flows too. Reviewed-by: Namjae Jeon Signed-off-by: Jaegeuk Kim --- diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c index f54b83b4d90b..590ea50c80a7 100644 --- a/fs/f2fs/checkpoint.c +++ b/fs/f2fs/checkpoint.c @@ -549,6 +549,10 @@ static void block_operations(struct f2fs_sb_info *sbi) .nr_to_write = LONG_MAX, .for_reclaim = 0, }; + struct blk_plug plug; + + blk_start_plug(&plug); + retry_flush_dents: mutex_lock_all(sbi); @@ -571,6 +575,7 @@ retry_flush_nodes: sync_node_pages(sbi, 0, &wbc); goto retry_flush_nodes; } + blk_finish_plug(&plug); } static void unblock_operations(struct f2fs_sb_info *sbi) diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index 1220b5c2ea21..eba7e84d1ffd 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -172,7 +172,7 @@ end_update: return; } -struct page *find_data_page(struct inode *inode, pgoff_t index) +struct page *find_data_page(struct inode *inode, pgoff_t index, bool sync) { struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb); struct address_space *mapping = inode->i_mapping; @@ -207,11 +207,14 @@ struct page *find_data_page(struct inode *inode, pgoff_t index) return page; } - err = f2fs_readpage(sbi, page, dn.data_blkaddr, READ_SYNC); - wait_on_page_locked(page); - if (!PageUptodate(page)) { - f2fs_put_page(page, 0); - return ERR_PTR(-EIO); + err = f2fs_readpage(sbi, page, dn.data_blkaddr, + sync ? READ_SYNC : READA); + if (sync) { + wait_on_page_locked(page); + if (!PageUptodate(page)) { + f2fs_put_page(page, 0); + return ERR_PTR(-EIO); + } } return page; } diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c index cd3342d4a3a7..3ddb1bc7d07a 100644 --- a/fs/f2fs/dir.c +++ b/fs/f2fs/dir.c @@ -148,7 +148,7 @@ static struct f2fs_dir_entry *find_in_level(struct inode *dir, for (; bidx < end_block; bidx++) { /* no need to allocate new dentry pages to all the indices */ - dentry_page = find_data_page(dir, bidx); + dentry_page = find_data_page(dir, bidx, true); if (IS_ERR(dentry_page)) { room = true; continue; diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index 06cc75c66c88..6283c8d77c2e 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -1023,7 +1023,7 @@ void destroy_checkpoint_caches(void); */ int reserve_new_block(struct dnode_of_data *); void update_extent_cache(block_t, struct dnode_of_data *); -struct page *find_data_page(struct inode *, pgoff_t); +struct page *find_data_page(struct inode *, pgoff_t, bool); struct page *get_lock_data_page(struct inode *, pgoff_t); struct page *get_new_data_page(struct inode *, pgoff_t, bool); int f2fs_readpage(struct f2fs_sb_info *, struct page *, block_t, int); diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index 0e56db2d3cc9..9dfcdab5ea7c 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -212,7 +212,7 @@ static void truncate_partial_data_page(struct inode *inode, u64 from) if (!offset) return; - page = find_data_page(inode, from >> PAGE_CACHE_SHIFT); + page = find_data_page(inode, from >> PAGE_CACHE_SHIFT, false); if (IS_ERR(page)) return; diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c index 6ed3263eeee8..25a1f7e593e0 100644 --- a/fs/f2fs/gc.c +++ b/fs/f2fs/gc.c @@ -386,6 +386,7 @@ static void gc_node_segment(struct f2fs_sb_info *sbi, next_step: entry = sum; + for (off = 0; off < sbi->blocks_per_seg; off++, entry++) { nid_t nid = le32_to_cpu(entry->nid); struct page *node_page; @@ -417,6 +418,7 @@ next_step: f2fs_put_page(node_page, 1); stat_inc_node_blk_count(sbi, 1); } + if (initial) { initial = false; goto next_step; @@ -545,6 +547,7 @@ static void gc_data_segment(struct f2fs_sb_info *sbi, struct f2fs_summary *sum, next_step: entry = sum; + for (off = 0; off < sbi->blocks_per_seg; off++, entry++) { struct page *data_page; struct inode *inode; @@ -582,7 +585,7 @@ next_step: continue; data_page = find_data_page(inode, - start_bidx + ofs_in_node); + start_bidx + ofs_in_node, false); if (IS_ERR(data_page)) goto next_iput; @@ -603,6 +606,7 @@ next_step: next_iput: iput(inode); } + if (++phase < 4) goto next_step; @@ -636,12 +640,15 @@ static void do_garbage_collect(struct f2fs_sb_info *sbi, unsigned int segno, { struct page *sum_page; struct f2fs_summary_block *sum; + struct blk_plug plug; /* read segment summary of victim */ sum_page = get_sum_page(sbi, segno); if (IS_ERR(sum_page)) return; + blk_start_plug(&plug); + sum = page_address(sum_page); switch (GET_SUM_TYPE((&sum->footer))) { @@ -652,6 +659,8 @@ static void do_garbage_collect(struct f2fs_sb_info *sbi, unsigned int segno, gc_data_segment(sbi, sum->entries, ilist, segno, gc_type); break; } + blk_finish_plug(&plug); + stat_inc_seg_count(sbi, GET_SUM_TYPE((&sum->footer))); stat_inc_call_count(sbi->stat_info); diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c index 5a825502b0b0..a0aa0446a237 100644 --- a/fs/f2fs/node.c +++ b/fs/f2fs/node.c @@ -89,10 +89,13 @@ static void ra_nat_pages(struct f2fs_sb_info *sbi, int nid) { struct address_space *mapping = sbi->meta_inode->i_mapping; struct f2fs_nm_info *nm_i = NM_I(sbi); + struct blk_plug plug; struct page *page; pgoff_t index; int i; + blk_start_plug(&plug); + for (i = 0; i < FREE_NID_PAGES; i++, nid += NAT_ENTRY_PER_BLOCK) { if (nid >= nm_i->max_nid) nid = 0; @@ -110,6 +113,7 @@ static void ra_nat_pages(struct f2fs_sb_info *sbi, int nid) f2fs_put_page(page, 0); } + blk_finish_plug(&plug); } static struct nat_entry *__lookup_nat_cache(struct f2fs_nm_info *nm_i, nid_t n) @@ -942,6 +946,7 @@ struct page *get_node_page_ra(struct page *parent, int start) { struct f2fs_sb_info *sbi = F2FS_SB(parent->mapping->host->i_sb); struct address_space *mapping = sbi->node_inode->i_mapping; + struct blk_plug plug; struct page *page; int err, i, end; nid_t nid; @@ -961,6 +966,8 @@ struct page *get_node_page_ra(struct page *parent, int start) else if (err == LOCKED_PAGE) goto page_hit; + blk_start_plug(&plug); + /* Then, try readahead for siblings of the desired node */ end = start + MAX_RA_NODE; end = min(end, NIDS_PER_BLOCK); @@ -971,6 +978,8 @@ struct page *get_node_page_ra(struct page *parent, int start) ra_node_page(sbi, nid); } + blk_finish_plug(&plug); + lock_page(page); page_hit: