f2fs: change default schedule timeout value

This patch changes default schedule timeout value from 20ms to 1ms,
in order to give caller more chances to check whether IO or non-IO
congestion condition has already been mitigable.

In addition, default interval of periodical discard submission is
kept to 20ms.

Signed-off-by: Chao Yu <[email protected]>
Signed-off-by: Jaegeuk Kim <[email protected]>

Author: chaseyu

fs/f2fs/f2fs.h

@@ -407,6 +407,8 @@ struct discard_entry {
 #define DEFAULT_DISCARD_GRANULARITY		16
 /* default maximum discard granularity of ordered discard, unit: block count */
 #define DEFAULT_MAX_ORDERED_DISCARD_GRANULARITY	16
+/* default interval of periodical discard submission */
+#define DEFAULT_DISCARD_INTERVAL	(msecs_to_jiffies(20))
 
 /* max discard pend list number */
 #define MAX_PLIST_NUM		512
@@ -656,8 +658,8 @@ enum {
 
 #define DEFAULT_RETRY_IO_COUNT	8	/* maximum retry read IO or flush count */
 
-/* IO/non-IO congestion wait timeout value, default: 20ms */
-#define	DEFAULT_SCHEDULE_TIMEOUT	(msecs_to_jiffies(20))
+/* IO/non-IO congestion wait timeout value, default: 1ms */
+#define	DEFAULT_SCHEDULE_TIMEOUT	(msecs_to_jiffies(1))
 
 /* timeout value injected, default: 1000ms */
 #define DEFAULT_FAULT_TIMEOUT	(msecs_to_jiffies(1000))

fs/f2fs/segment.c

@@ -3471,7 +3471,7 @@ static unsigned int __issue_discard_cmd_range(struct f2fs_sb_info *sbi,
 			blk_finish_plug(&plug);
 			mutex_unlock(&dcc->cmd_lock);
 			trimmed += __wait_all_discard_cmd(sbi, NULL);
-			f2fs_schedule_timeout(DEFAULT_SCHEDULE_TIMEOUT);
+			f2fs_schedule_timeout(DEFAULT_DISCARD_INTERVAL);
 			goto next;
 		}
 skip: