From: Sahitya Tummala Date: Fri, 31 Aug 2018 09:39:26 +0000 (+0530) Subject: f2fs: fix unnecessary periodic wakeup of discard thread when dev is busy X-Git-Tag: v4.20-rc1~138^2~59 X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=abde73c718293b83c23b2ca137f18b3f8650a553;p=uclinux-h8%2Flinux.git 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 --- 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; }