From a57e564d14d9d123b2dd4ff1c933da0d900e0b1d Mon Sep 17 00:00:00 2001 From: Jin Xu Date: Fri, 13 Sep 2013 08:38:54 +0800 Subject: f2fs: optimize the victim searching loop slightly Since the MAX_VICTIM_SEARCH has been enlarged from 20 to 4096, the victim searching overhead will be increased much than before, especially for SSR that searches victim for use quiet often. This patch intends to reduce the overhead a little bit by: - make the get_gc_cost a inline routine to reduce function call overhead - reduce multiplication and division operations - reduce unnecessary comparison operation Signed-off-by: Jin Xu Signed-off-by: Jaegeuk Kim --- fs/f2fs/gc.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) (limited to 'fs/f2fs') diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c index 2f157e883687..fbad96846c7c 100644 --- a/fs/f2fs/gc.c +++ b/fs/f2fs/gc.c @@ -236,8 +236,8 @@ static unsigned int get_cb_cost(struct f2fs_sb_info *sbi, unsigned int segno) return UINT_MAX - ((100 * (100 - u) * age) / (100 + u)); } -static unsigned int get_gc_cost(struct f2fs_sb_info *sbi, unsigned int segno, - struct victim_sel_policy *p) +static inline unsigned int get_gc_cost(struct f2fs_sb_info *sbi, + unsigned int segno, struct victim_sel_policy *p) { if (p->alloc_mode == SSR) return get_seg_entry(sbi, segno)->ckpt_valid_blocks; @@ -293,7 +293,11 @@ static int get_victim_by_default(struct f2fs_sb_info *sbi, } break; } - p.offset = ((segno / p.ofs_unit) * p.ofs_unit) + p.ofs_unit; + + p.offset = segno + p.ofs_unit; + if (p.ofs_unit > 1) + p.offset -= segno % p.ofs_unit; + secno = GET_SECNO(sbi, segno); if (sec_usage_check(sbi, secno)) @@ -306,10 +310,9 @@ static int get_victim_by_default(struct f2fs_sb_info *sbi, if (p.min_cost > cost) { p.min_segno = segno; p.min_cost = cost; - } - - if (cost == max_cost) + } else if (unlikely(cost == max_cost)) { continue; + } if (nsearched++ >= p.max_search) { sbi->last_victim[p.gc_mode] = segno; -- cgit v1.2.3