Re: [PATCH] tty: n_tty: convert the full VTIME interval to jiffies

[Greg KH <gregkh@linuxfoundation.org>]

On Thu, Oct 29, 2026 at 12:52:59AM -0700, Hungyu Lin wrote:
> > Ok, and has it ever reported problems with this rounding error?  This is
> > very old code, changing it needs to be done only if an issue is actually
> > noticed as it might be relied on, right?
> 
> I don't have a report from users of those systems. I found this by
> inspection and reproduced the early timeout using PTYs under QEMU.
> 
> For comparison, FreeBSD's original VMIN/VTIME code keeps the timeout
> in microseconds and rounds the remaining interval up when
> converting to ticks:
> https://github.com/freebsd/freebsd-src/commit/d32198f15b39a0f6dc29229ba4925d67d136956e
> 
> I understand that this doesn't rule out applications depending on the
> existing Linux timing. Would you consider the conversion correction
> worthwhile on that basis?

Unless you can prove that this is causing a problem, I would suggest
leaving this as-is please.  Modifying user-visable behaviour is very
tricky.

thanks,

greg k-h