From abde73c718293b83c23b2ca137f18b3f8650a553 Mon Sep 17 00:00:00 2001 From: Sahitya Tummala Date: Fri, 31 Aug 2018 15:09:26 +0530 Subject: [PATCH] f2fs: fix unnecessary periodic wakeup of discard thread when dev is busy When dev is busy, discard thread wake up timeout can be aligned with the exact time that it needs to wait for dev to come out of busy. This helps to avoid unnecessary periodic wakeups and thus save some power. Signed-off-by: Sahitya Tummala Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim --- fs/f2fs/segment.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c index c372ff755818..f36a4b71595f 100644 --- a/fs/f2fs/segment.c +++ b/fs/f2fs/segment.c @@ -1564,6 +1564,8 @@ static int issue_discard_thread(void *data) struct discard_policy dpolicy; unsigned int wait_ms = DEF_MIN_DISCARD_ISSUE_TIME; int issued; + unsigned long interval = sbi->interval_time[REQ_TIME] * HZ; + long delta; set_freezable(); @@ -1600,7 +1602,11 @@ static int issue_discard_thread(void *data) __wait_all_discard_cmd(sbi, &dpolicy); wait_ms = dpolicy.min_interval; } else if (issued == -1){ - wait_ms = dpolicy.mid_interval; + delta = (sbi->last_time[REQ_TIME] + interval) - jiffies; + if (delta > 0) + wait_ms = jiffies_to_msecs(delta); + else + wait_ms = dpolicy.mid_interval; } else { wait_ms = dpolicy.max_interval; }