Re: [PATCH 4/4] rust: time: add `pr_warn_once!` for clamped delta in `fsleep`

[Greg KH <gregkh@linuxfoundation.org>]

On Mon, Apr 06, 2026 at 12:39:12PM +0200, Miguel Ojeda wrote:
> On Thu, Feb 26, 2026 at 3:36 PM Greg KH <gregkh@linuxfoundation.org> wrote:
> >
> > WARN_ONCE() also will panic the machine if panic_on_warn is enabled.  As
> > it is done in a few billion Linux systems right now :(
> >
> > So be very careful about that.
> 
> Coming back to this...
> 
> I think we should settle for cases like this (i.e. "Erroneous
> Behavior") to use `debug_assert!` plus `pr_warn_once!`.
> 
> That way in normal builds, we just print a warning once, no risk of
> `WARN_ONCE()`. And in truly debug builds, we assert.

Who would ever build a "truly debug build"?  That's the overall problem
we have tried to fix up, no user will do a new build for things, so we
have dynamic debugging now.  I think only the mm core still has an
overly-strict debug mode that only the mm developers run, and even then,
there have been arguments it should be removed.

> This should make it easier to add such EB in most cases where needed,
> and if someone really wants `WARN_ONCE()` or similar, then they can do
> it explicitly.

Sure, that's fine, but note that this will crash and should NEVER happen
if it can be user triggered.  And if you are warning, well, why not just
handle the issue, print out a message, and continue on?  Why reboot
anything?

thanks,

greg k-h