Messages in this thread | | | From | David Laight <> | Subject | RE: [GIT PULL] gcc-plugin updates for v4.19-rc1 | Date | Thu, 16 Aug 2018 09:51:41 +0000 |
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From: Linus Torvalds > Sent: 15 August 2018 21:19 ... > But if people run things on real machines, then BUG() is absolutely > the last thing you EVER want to do for "debugging".
I'm not sure you want it on a live system either. Live systems are where the 'hard' bugs show up.
I've just spent a couple of days pulling my hair out trying to work out how to debug a customer system that was locking up solid when running some new (and not completely testable by us) kernel code.
At 4am I suddenly realised that the distribution they are using might be enabling 'panic_on_oops' by default. Turning that off showed what was going wrong.
It wouldn't be as bad if Linux implemented 'dump to swap'.
For 'errors' that aren't completely fatal the system could 'fast shutdown' a lot of processes (maybe just refuse to schedule them) while leaving enough running for fault diagnosis. I'm not sure how you'd decide what to allow to run though.
David
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