[PATCH 2/2] f2fs: add to account skip count of background GC
From: Chao Yu
Date: Sat Sep 29 2018 - 06:31:50 EST
This patch adds to account skip count of background GC, and show stat
info via 'status' debugfs entry.
Signed-off-by: Chao Yu <yuchao0@xxxxxxxxxx>
---
fs/f2fs/debug.c | 4 ++++
fs/f2fs/f2fs.h | 7 +++++++
fs/f2fs/gc.c | 14 +++++++++++---
3 files changed, 22 insertions(+), 3 deletions(-)
diff --git a/fs/f2fs/debug.c b/fs/f2fs/debug.c
index da1cabbc4973..75bc62edc4c1 100644
--- a/fs/f2fs/debug.c
+++ b/fs/f2fs/debug.c
@@ -101,6 +101,8 @@ static void update_general_status(struct f2fs_sb_info *sbi)
si->avail_nids = NM_I(sbi)->available_nids;
si->alloc_nids = NM_I(sbi)->nid_cnt[PREALLOC_NID];
si->bg_gc = sbi->bg_gc;
+ si->io_skip_bggc = sbi->io_skip_bggc;
+ si->other_skip_bggc = sbi->other_skip_bggc;
si->skipped_atomic_files[BG_GC] = sbi->skipped_atomic_files[BG_GC];
si->skipped_atomic_files[FG_GC] = sbi->skipped_atomic_files[FG_GC];
si->util_free = (int)(free_user_blocks(sbi) >> sbi->log_blocks_per_seg)
@@ -355,6 +357,8 @@ static int stat_show(struct seq_file *s, void *v)
si->skipped_atomic_files[BG_GC] +
si->skipped_atomic_files[FG_GC],
si->skipped_atomic_files[BG_GC]);
+ seq_printf(s, "BG skip : IO: %u, Other: %u\n",
+ si->io_skip_bggc, si->other_skip_bggc);
seq_puts(s, "\nExtent Cache:\n");
seq_printf(s, " - Hit Count: L1-1:%llu L1-2:%llu L2:%llu\n",
si->hit_largest, si->hit_cached,
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 0f82f342e514..807a2e34543c 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -1284,6 +1284,8 @@ struct f2fs_sb_info {
atomic_t max_aw_cnt; /* max # of atomic writes */
atomic_t max_vw_cnt; /* max # of volatile writes */
int bg_gc; /* background gc calls */
+ unsigned int io_skip_bggc; /* skip background gc for in-flight IO */
+ unsigned int other_skip_bggc; /* skip background gc for other reasons */
unsigned int ndirty_inode[NR_INODE_TYPE]; /* # of dirty inodes */
#endif
spinlock_t stat_lock; /* lock for stat operations */
@@ -3127,6 +3129,7 @@ struct f2fs_stat_info {
int free_nids, avail_nids, alloc_nids;
int total_count, utilization;
int bg_gc, nr_wb_cp_data, nr_wb_data;
+ unsigned int io_skip_bggc, other_skip_bggc;
int nr_flushing, nr_flushed, flush_list_empty;
int nr_discarding, nr_discarded;
int nr_discard_cmd;
@@ -3164,6 +3167,8 @@ static inline struct f2fs_stat_info *F2FS_STAT(struct f2fs_sb_info *sbi)
#define stat_inc_bg_cp_count(si) ((si)->bg_cp_count++)
#define stat_inc_call_count(si) ((si)->call_count++)
#define stat_inc_bggc_count(sbi) ((sbi)->bg_gc++)
+#define stat_io_skip_bggc_count(sbi) ((sbi)->io_skip_bggc++)
+#define stat_other_skip_bggc_count(sbi) ((sbi)->other_skip_bggc++)
#define stat_inc_dirty_inode(sbi, type) ((sbi)->ndirty_inode[type]++)
#define stat_dec_dirty_inode(sbi, type) ((sbi)->ndirty_inode[type]--)
#define stat_inc_total_hit(sbi) (atomic64_inc(&(sbi)->total_hit_ext))
@@ -3280,6 +3285,8 @@ void f2fs_destroy_root_stats(void);
#define stat_inc_bg_cp_count(si) do { } while (0)
#define stat_inc_call_count(si) do { } while (0)
#define stat_inc_bggc_count(si) do { } while (0)
+#define stat_io_skip_bggc_count(sbi) do { } while (0)
+#define stat_other_skip_bggc_count(sbi) do { } while (0)
#define stat_inc_dirty_inode(sbi, type) do { } while (0)
#define stat_dec_dirty_inode(sbi, type) do { } while (0)
#define stat_inc_total_hit(sb) do { } while (0)
diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index 91896d979972..21e42554bdb8 100644
--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -40,13 +40,16 @@ static int gc_thread_func(void *data)
if (gc_th->gc_wake)
gc_th->gc_wake = 0;
- if (try_to_freeze())
+ if (try_to_freeze()) {
+ stat_other_skip_bggc_count(sbi);
continue;
+ }
if (kthread_should_stop())
break;
if (sbi->sb->s_writers.frozen >= SB_FREEZE_WRITE) {
increase_sleep_time(gc_th, &wait_ms);
+ stat_other_skip_bggc_count(sbi);
continue;
}
@@ -55,8 +58,10 @@ static int gc_thread_func(void *data)
f2fs_stop_checkpoint(sbi, false);
}
- if (!sb_start_write_trylock(sbi->sb))
+ if (!sb_start_write_trylock(sbi->sb)) {
+ stat_other_skip_bggc_count(sbi);
continue;
+ }
/*
* [GC triggering condition]
@@ -77,12 +82,15 @@ static int gc_thread_func(void *data)
goto do_gc;
}
- if (!mutex_trylock(&sbi->gc_mutex))
+ if (!mutex_trylock(&sbi->gc_mutex)) {
+ stat_other_skip_bggc_count(sbi);
goto next;
+ }
if (!is_idle(sbi, GC_TIME)) {
increase_sleep_time(gc_th, &wait_ms);
mutex_unlock(&sbi->gc_mutex);
+ stat_io_skip_bggc_count(sbi);
goto next;
}
--
2.18.0.rc1