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Date: Mon, 8 Jun 2015 17:26:16 +0300
Message-ID: <CACVxJT930rX5pRi4OQbG51cuV3Y6K9jRit0K80FCohivLfrjJw@mail.gmail.com>
Subject: Re: [PATCH] debug: Deprecate BUG_ON() use in new code, introduce CRASH_ON()
From: Alexey Dobriyan <adobriyan@gmail.com>
To: Ingo Molnar <mingo@kernel.org>
Cc: Linux Kernel <linux-kernel@vger.kernel.org>, lou_langholtz@me.com,
        htejun@gmail.com, Linus Torvalds <torvalds@linux-foundation.org>,
        holler@ahsoftware.de
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Ingo Molnar wrote:

> These days a BUG_ON() is almost always fatal due to unreleased locks,
> plus we still don't print kernel crashes to the graphical console,
> so they are silent hard lockups in 99% of the cases.

Is it a regression?

I've just tested with "echo c >/proc/sysrq-trigger" and
kernel.panic_on_oops=1 and the box just hanged. But I clearly remember
it started to work at some point and it was a miracle. Recently a colleague
of mine show such graphical panic (most of it as always scrolled away BTW).

It's usual setup with i915 driver, X and fbconsole which is never used.

As for BUG_ON() I hope rule will be relaxed for "not under locks" situations
and something will be done with inevitable miryads of trivial patches.

Count them:

        $ chgrep -e BUG_ON -w -n  | wc -l
        9660
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