From: Jason Gunthorpe > Sent: 09 August 2022 20:08 > > On Tue, Aug 09, 2022 at 11:59:45AM -0700, Linus Torvalds wrote: > > > But as a very good approximation, the rule is "absolutely no new > > BUG_ON() calls _ever_". Because I really cannot see a single case > > where "proper error handling and WARN_ON_ONCE()" isn't the right > > thing. > > Parallel to this discussion I've had ones where people more or less > say > > Since BUG_ON crashes the machine and Linus says that crashing the > machine is bad, WARN_ON will also crash the machine if you set the > panic_on_warn parameter, so it is also bad, thus we shouldn't use > anything. > > I've generally maintained that people who set the panic_on_warn *want* > these crashes, because that is the entire point of it. So we should > use WARN_ON with an error recovery for "can't happen" assertions like > these. I think it is what you are saying here. They don't necessarily want the crashes, it is more the people who built the distribution think they want the crashes. I have had issues with a customer system (with our drivers) randomly locking up. Someone had decided that 'PANIC_ON_OOPS' was a good idea but hadn't enabled anything to actually take the dump. So instead of a diagnosable problem (and a 'doh' moment) you get several weeks of head scratching and a very annoyed user. David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)
