From b7250d2d845822466356f7f22a650bf807090d7e Mon Sep 17 00:00:00 2001 From: Jaegeuk Kim Date: Tue, 5 Feb 2013 13:19:28 +0900 Subject: f2fs: fix calculation of max. gc cost in the SSR case In the SSR case, the max gc cost should be the number of pages in a segment. Otherwise, f2fs is able to fail getting dirty segments frequently for SSR. In get_victim_by_default() previously, while(1) { ... cost = get_gc_cost(); <- cost is between 0 ~ 512. ... if (cost == get_max_cost(sbi, &p)) <- max cost is UINT_MAX due to GC_CB type continue; if (nsearched++ >= MAX_VICTIM_SEARCH) break; } So, if there are a number of fully valid segments in series, f2fs cannot skip those segments by comparing the cost and max cost of each segment. Note that, the cost is the number of valid blocks at the time of the last checkpoint. Signed-off-by: Jaegeuk Kim --- fs/f2fs/gc.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'fs/f2fs') diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c index 52d3a391b922..94b8a0c48453 100644 --- a/fs/f2fs/gc.c +++ b/fs/f2fs/gc.c @@ -146,6 +146,9 @@ static void select_policy(struct f2fs_sb_info *sbi, int gc_type, static unsigned int get_max_cost(struct f2fs_sb_info *sbi, struct victim_sel_policy *p) { + /* SSR allocates in a segment unit */ + if (p->alloc_mode == SSR) + return 1 << sbi->log_blocks_per_seg; if (p->gc_mode == GC_GREEDY) return (1 << sbi->log_blocks_per_seg) * p->ofs_unit; else if (p->gc_mode == GC_CB) -- cgit v1.2.3