RE: Removing Mandatory Locks

From: Linus Torvalds

Sent: 19 August 2021 23:33

On Thu, Aug 19, 2021 at 2:43 PM Jeff Layton [off-list ref] wrote:

quoted

What sort of big, ugly warning did you have in mind?

I originally thought WARN_ON_ONCE() just to get the distro automatic
error handling involved, but it would probably be a big problem for
the people who end up having panic-on-warn or something.

Even panic-on-oops is a PITA.
Took us weeks to realise that a customer system that was randomly
rebooting was 'just' having a boring NULL pointer access.
 

So probably just a "make it a big box" thing that stands out, kind of
what lockdep etc does with

        pr_warn("======...====\n");

around the messages..

I don't know if distros have some pattern we could use that would end
up being something that gets reported to the user?

Will users even see it?
A lot of recent distro installs try very hard to hide all the kernel
messages.
OTOH I guess '-o mand' is unlikely to be set on any of those systems.

	David

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