f2fs: avoid BG_GC in f2fs_balance_fs
If many threads hit has_not_enough_free_secs() in f2fs_balance_fs() at the same
time, all the threads would do FG_GC or BG_GC.
In this critical path, we totally don't need to do BG_GC at all.
Let's avoid that.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index a7b2c13..36f6cfc 100644
--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -82,7 +82,7 @@ static int gc_thread_func(void *data)
stat_inc_bggc_count(sbi);
/* if return value is not zero, no victim was selected */
- if (f2fs_gc(sbi, test_opt(sbi, FORCE_FG_GC)))
+ if (f2fs_gc(sbi, test_opt(sbi, FORCE_FG_GC), true))
wait_ms = gc_th->no_gc_sleep_time;
trace_f2fs_background_gc(sbi->sb, wait_ms,
@@ -909,7 +909,7 @@ static int do_garbage_collect(struct f2fs_sb_info *sbi,
return sec_freed;
}
-int f2fs_gc(struct f2fs_sb_info *sbi, bool sync)
+int f2fs_gc(struct f2fs_sb_info *sbi, bool sync, bool background)
{
unsigned int segno;
int gc_type = sync ? FG_GC : BG_GC;
@@ -950,6 +950,9 @@ int f2fs_gc(struct f2fs_sb_info *sbi, bool sync)
if (ret)
goto stop;
}
+ } else if (gc_type == BG_GC && !background) {
+ /* f2fs_balance_fs doesn't need to do BG_GC in critical path. */
+ goto stop;
}
if (segno == NULL_SEGNO && !__get_victim(sbi, &segno, gc_type))