f2fs: introduce gc_urgent mode for background GC
This patch adds a sysfs entry to control urgent mode for background GC.
If this is set, background GC thread conducts GC with gc_urgent_sleep_time
all the time.
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index 620dca4..8da7c14 100644
--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -35,9 +35,14 @@ static int gc_thread_func(void *data)
set_freezable();
do {
wait_event_interruptible_timeout(*wq,
- kthread_should_stop() || freezing(current),
+ kthread_should_stop() || freezing(current) ||
+ gc_th->gc_wake,
msecs_to_jiffies(wait_ms));
+ /* give it a try one time */
+ if (gc_th->gc_wake)
+ gc_th->gc_wake = 0;
+
if (try_to_freeze())
continue;
if (kthread_should_stop())
@@ -74,6 +79,11 @@ static int gc_thread_func(void *data)
if (!mutex_trylock(&sbi->gc_mutex))
goto next;
+ if (gc_th->gc_urgent) {
+ wait_ms = gc_th->urgent_sleep_time;
+ goto do_gc;
+ }
+
if (!is_idle(sbi)) {
increase_sleep_time(gc_th, &wait_ms);
mutex_unlock(&sbi->gc_mutex);
@@ -84,7 +94,7 @@ static int gc_thread_func(void *data)
decrease_sleep_time(gc_th, &wait_ms);
else
increase_sleep_time(gc_th, &wait_ms);
-
+do_gc:
stat_inc_bggc_count(sbi);
/* if return value is not zero, no victim was selected */
@@ -115,11 +125,14 @@ int start_gc_thread(struct f2fs_sb_info *sbi)
goto out;
}
+ gc_th->urgent_sleep_time = DEF_GC_THREAD_URGENT_SLEEP_TIME;
gc_th->min_sleep_time = DEF_GC_THREAD_MIN_SLEEP_TIME;
gc_th->max_sleep_time = DEF_GC_THREAD_MAX_SLEEP_TIME;
gc_th->no_gc_sleep_time = DEF_GC_THREAD_NOGC_SLEEP_TIME;
gc_th->gc_idle = 0;
+ gc_th->gc_urgent = 0;
+ gc_th->gc_wake= 0;
sbi->gc_thread = gc_th;
init_waitqueue_head(&sbi->gc_thread->gc_wait_queue_head);