From 2db2388fcf0d880bd7160264274ed873baec4f0d Mon Sep 17 00:00:00 2001 From: Chao Yu Date: Mon, 12 Oct 2015 17:07:33 +0800 Subject: [PATCH] f2fs: readahead for free nids building When there is no free nid in nid cache, all new node allocaters stop their job to wait for reloading of free nids, however reloading is synchronous as we will read 4 NAT pages for building nid cache, it cause the long latency. This patch tries to readahead more NAT pages with READA request flag after reloading of free nids. It helps to improve performance when users allocate node id intensively. Env: Sandisk 32G sd card time for i in `seq 1 60000`; { echo -n > /mnt/f2fs/$i; echo XXXXXX > /mnt/f2fs/$i;} Before: real 0m2.814s user 0m1.220s sys 0m1.536s After: real 0m2.711s user 0m1.136s sys 0m1.568s Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim --- fs/f2fs/node.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c index ad98e35f3fcb..14f46067817a 100644 --- a/fs/f2fs/node.c +++ b/fs/f2fs/node.c @@ -1560,6 +1560,9 @@ static void build_free_nids(struct f2fs_sb_info *sbi) remove_free_nid(nm_i, nid); } mutex_unlock(&curseg->curseg_mutex); + + ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nm_i->next_scan_nid), + FREE_NID_PAGES, META_NAT, false); } /*