If f2fs aborts BG_GC, then the section bit of victim_secmap will be set, which will cause the section skipped in the future get_victim of BG_GC. In a worst case that each section in the victim_secmap is set and there are enough free sections (so FG_GC can not be triggered), then BG_GC will skip all the sections and cannot find any victims, causing BG_GC failed each time. Besides, SSR also uses BG_GC to get ssr segment, if many sections in the victim_secmap are set, then SSR cannot get a proper ssr segment to allocate blocks, which makes SSR inefficiently. To fix this problem, we can add cur_victim_sec for BG_GC similar like that in FG_GC to avoid selecting the same section repeatedly.
Signed-off-by: Yunlong Song <[email protected]> --- fs/f2fs/f2fs.h | 3 ++- fs/f2fs/gc.c | 15 +++++++++------ fs/f2fs/segment.h | 3 ++- fs/f2fs/super.c | 3 ++- include/trace/events/f2fs.h | 18 ++++++++++++------ 5 files changed, 27 insertions(+), 15 deletions(-) diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index 57a8851..f8a7b42 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -1217,7 +1217,8 @@ struct f2fs_sb_info { /* for cleaning operations */ struct mutex gc_mutex; /* mutex for GC */ struct f2fs_gc_kthread *gc_thread; /* GC thread */ - unsigned int cur_victim_sec; /* current victim section num */ + unsigned int cur_fg_victim_sec; /* current FG_GC victim section num */ + unsigned int cur_bg_victim_sec; /* current BG_GC victim section num */ unsigned int gc_mode; /* current GC state */ /* for skip statistic */ unsigned long long skipped_atomic_files[2]; /* FG_GC and BG_GC */ diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c index 2ba470d..705d419 100644 --- a/fs/f2fs/gc.c +++ b/fs/f2fs/gc.c @@ -367,8 +367,6 @@ static int get_victim_by_default(struct f2fs_sb_info *sbi, if (sec_usage_check(sbi, secno)) goto next; - if (gc_type == BG_GC && test_bit(secno, dirty_i->victim_secmap)) - goto next; cost = get_gc_cost(sbi, segno, &p); @@ -391,14 +389,17 @@ static int get_victim_by_default(struct f2fs_sb_info *sbi, if (p.alloc_mode == LFS) { secno = GET_SEC_FROM_SEG(sbi, p.min_segno); if (gc_type == FG_GC) - sbi->cur_victim_sec = secno; - else + sbi->cur_fg_victim_sec = secno; + else { set_bit(secno, dirty_i->victim_secmap); + sbi->cur_bg_victim_sec = secno; + } } *result = (p.min_segno / p.ofs_unit) * p.ofs_unit; trace_f2fs_get_victim(sbi->sb, type, gc_type, &p, - sbi->cur_victim_sec, + sbi->cur_fg_victim_sec, + sbi->cur_bg_victim_sec, prefree_segments(sbi), free_segments(sbi)); } out: @@ -1098,7 +1099,9 @@ int f2fs_gc(struct f2fs_sb_info *sbi, bool sync, } if (gc_type == FG_GC) - sbi->cur_victim_sec = NULL_SEGNO; + sbi->cur_fg_victim_sec = NULL_SEGNO; + else + sbi->cur_bg_victim_sec = NULL_SEGNO; if (!sync) { if (has_not_enough_free_secs(sbi, sec_freed, 0)) { diff --git a/fs/f2fs/segment.h b/fs/f2fs/segment.h index 5049551..b21bb96 100644 --- a/fs/f2fs/segment.h +++ b/fs/f2fs/segment.h @@ -787,7 +787,8 @@ static inline block_t sum_blk_addr(struct f2fs_sb_info *sbi, int base, int type) static inline bool sec_usage_check(struct f2fs_sb_info *sbi, unsigned int secno) { - if (IS_CURSEC(sbi, secno) || (sbi->cur_victim_sec == secno)) + if (IS_CURSEC(sbi, secno) || (sbi->cur_fg_victim_sec == secno) || + (sbi->cur_bg_victim_sec == secno)) return true; return false; } diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c index 7187885..ef69ebf 100644 --- a/fs/f2fs/super.c +++ b/fs/f2fs/super.c @@ -2386,7 +2386,8 @@ static void init_sb_info(struct f2fs_sb_info *sbi) sbi->root_ino_num = le32_to_cpu(raw_super->root_ino); sbi->node_ino_num = le32_to_cpu(raw_super->node_ino); sbi->meta_ino_num = le32_to_cpu(raw_super->meta_ino); - sbi->cur_victim_sec = NULL_SECNO; + sbi->cur_fg_victim_sec = NULL_SECNO; + sbi->cur_bg_victim_sec = NULL_SECNO; sbi->max_victim_search = DEF_MAX_VICTIM_SEARCH; sbi->dir_level = DEF_DIR_LEVEL; diff --git a/include/trace/events/f2fs.h b/include/trace/events/f2fs.h index 7956989..0f01f82 100644 --- a/include/trace/events/f2fs.h +++ b/include/trace/events/f2fs.h @@ -693,10 +693,12 @@ TRACE_EVENT(f2fs_get_victim, TP_PROTO(struct super_block *sb, int type, int gc_type, - struct victim_sel_policy *p, unsigned int pre_victim, + struct victim_sel_policy *p, unsigned int pre_fg_victim, + unsigned int pre_bg_victim, unsigned int prefree, unsigned int free), - TP_ARGS(sb, type, gc_type, p, pre_victim, prefree, free), + TP_ARGS(sb, type, gc_type, p, pre_fg_victim, pre_bg_victim, + prefree, free), TP_STRUCT__entry( __field(dev_t, dev) @@ -707,7 +709,8 @@ __field(unsigned int, victim) __field(unsigned int, cost) __field(unsigned int, ofs_unit) - __field(unsigned int, pre_victim) + __field(unsigned int, pre_fg_victim) + __field(unsigned int, pre_bg_victim) __field(unsigned int, prefree) __field(unsigned int, free) ), @@ -721,14 +724,16 @@ __entry->victim = p->min_segno; __entry->cost = p->min_cost; __entry->ofs_unit = p->ofs_unit; - __entry->pre_victim = pre_victim; + __entry->pre_fg_victim = pre_fg_victim; + __entry->pre_bg_victim = pre_bg_victim; __entry->prefree = prefree; __entry->free = free; ), TP_printk("dev = (%d,%d), type = %s, policy = (%s, %s, %s), " "victim = %u, cost = %u, ofs_unit = %u, " - "pre_victim_secno = %d, prefree = %u, free = %u", + "pre_fg_victim_secno = %d, pre_bg_victim_secno = %d, " + "prefree = %u, free = %u", show_dev(__entry->dev), show_data_type(__entry->type), show_gc_type(__entry->gc_type), @@ -737,7 +742,8 @@ __entry->victim, __entry->cost, __entry->ofs_unit, - (int)__entry->pre_victim, + (int)__entry->pre_fg_victim, + (int)__entry->pre_bg_victim, __entry->prefree, __entry->free) ); -- 1.8.5.2 ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Linux-f2fs-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
