Commit fb8a7e94 authored by Nikolay Borisov's avatar Nikolay Borisov Committed by David Sterba
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btrfs: calculate more accurate remaining time to sleep in transaction_kthread 



If transaction_kthread is woken up before btrfs_fs_info::commit_interval
seconds have elapsed it will sleep for a fixed period of 5 seconds. This
is not a problem per-se but is not accurate. Instead the code should
sleep for an interval which guarantees on next wakeup commit_interval
would have passed. Since time tracking is not precise subtract 1 second
from delta to ensure the delay we end up waiting will be longer than
than the wake up period.

Signed-off-by: default avatarNikolay Borisov <nborisov@suse.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 643900be

fs/btrfs/disk-io.c

+3 −1
Original line number Diff line number Diff line
@@ -1794,7 +1794,9 @@ static int transaction_kthread(void *arg) 
		if (cur->state < TRANS_STATE_COMMIT_START &&

		    delta < fs_info->commit_interval) {

			spin_unlock(&fs_info->trans_lock);

			delay = msecs_to_jiffies(5000);

			delay -= msecs_to_jiffies((delta - 1) * 1000);

			delay = min(delay,

				    msecs_to_jiffies(fs_info->commit_interval * 1000));

			goto sleep;

		}

		transid = cur->transid;