Re: [vfs/vfs.all PATCH] writeback: use round_jiffies_relative for dirtytime_work

[Jan Kara]

On Tue 13-01-26 16:26:14, Zhao Mengmeng wrote:
> From: Zhao Mengmeng <zhaomengmeng@xxxxxxxxxx>
> 
> The dirtytime_work is a background housekeeping task that flushes dirty
> inodes, using round_jiffies_relative() will allow kernel to batch this
> work with other aligned system tasks, reducing power consumption.
> 
> Signed-off-by: Zhao Mengmeng <zhaomengmeng@xxxxxxxxxx>

Makes sense. Feel free to add:

Reviewed-by: Jan Kara <jack@xxxxxxx>

								Honza

> ---
>  fs/fs-writeback.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
> index ea95f527aace..a32d354152d0 100644
> --- a/fs/fs-writeback.c
> +++ b/fs/fs-writeback.c
> @@ -2504,7 +2504,8 @@ static void wakeup_dirtytime_writeback(struct work_struct *w)
>  	}
>  	rcu_read_unlock();
>  	if (dirtytime_expire_interval)
> -		schedule_delayed_work(&dirtytime_work, dirtytime_expire_interval * HZ);
> +		schedule_delayed_work(&dirtytime_work,
> +				      round_jiffies_relative(dirtytime_expire_interval * HZ));
>  }
>  
>  static int dirtytime_interval_handler(const struct ctl_table *table, int write,
> @@ -2536,7 +2537,8 @@ static const struct ctl_table vm_fs_writeback_table[] = {
>  static int __init start_dirtytime_writeback(void)
>  {
>  	if (dirtytime_expire_interval)
> -		schedule_delayed_work(&dirtytime_work, dirtytime_expire_interval * HZ);
> +		schedule_delayed_work(&dirtytime_work,
> +				      round_jiffies_relative(dirtytime_expire_interval * HZ));
>  	register_sysctl_init("vm", vm_fs_writeback_table);
>  	return 0;
>  }
> -- 
> 2.43.0
> 
-- 
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR