Re: [ 02/42] TTY: do not update atime/mtime on read/write

Jiri Slaby
2013-05-01T05:23:13Z

On 05/01/2013 03:41 AM, Linus Torvalds wrote:
> On Tue, Apr 30, 2013 at 5:57 PM, Linus Torvalds
> <torvalds@linux-foundation.org> wrote:
>>
>> Patch is whitespace-damaged and totally untested! Caveat applicator.
>
> Ok, so it's still whitespace-damaged, but it seems to work. The
> appended has the "8 second rule" too..
>
> Comments?

Yeah, looks good to me.

> --- snip snip ---
> drivers/tty/pty.c | 3 +++
> drivers/tty/tty_io.c | 4 ++--
> 2 files changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c
> index a62798fcc014..59bfaecc4e14 100644
> --- a/drivers/tty/pty.c
> +++ b/drivers/tty/pty.c
> @@ -681,6 +681,9 @@ static int ptmx_open(struct inode *inode, struct file *filp)
>
> nonseekable_open(inode, filp);
>
> + /* We refuse fsnotify events on ptmx, since it's a shared resource */
> + filp->f_mode |= FMODE_NONOTIFY;
> +
> retval = tty_alloc_file(filp);
> if (retval)
> return retval;
> diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
> index 97ebc8c5864e..6464029e4860 100644
> --- a/drivers/tty/tty_io.c
> +++ b/drivers/tty/tty_io.c
> @@ -988,10 +988,10 @@ void start_tty(struct tty_struct *tty)
>
> EXPORT_SYMBOL(start_tty);
>
> +/* We limit tty time update visibility to every 8 seconds or so. */
> static void tty_update_time(struct timespec *time)
> {
> - unsigned long sec = get_seconds();
> - sec -= sec % 60;
> + unsigned long sec = get_seconds() & ~7;
> if ((long)(sec - time->tv_sec) > 0)
> time->tv_sec = sec;
> }
>

thanks,
--
js
suse labs