Re: BUG_ON() in workingset_node_shadows_dec() triggers

From	Linus Torvalds <torvalds@linux-foundation.org>
Newsgroups	linux.kernel
Subject	Re: BUG_ON() in workingset_node_shadows_dec() triggers
Date	2016-10-05 21:20 +0200
Message-ID	<soZTr-5Rt-15@gated-at.bofh.it> (permalink)
References	(1 earlier) <soKrn-2ZC-1@gated-at.bofh.it> <soL45-3sX-3@gated-at.bofh.it> <soNfz-4TI-1@gated-at.bofh.it> <soWLT-2S6-7@gated-at.bofh.it> <soZJM-5KL-19@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On Wed, Oct 5, 2016 at 12:06 PM, Willy Tarreau <w@1wt.eu> wrote:
>
> I have the same doubts, so at least I would not want to run the "sed"
> immediately, at least to keep the initial intent. But I think everyone
> is right in is own yard when he puts a BUG_ON() when he doesn't know
> how to handle an unsafe situation, he's wrong from a global perspective.

Yes. And as you say, even when the developer might be right in sone
situations, you'd easily still be wrong for the same code in some
other situation.

Quite frankly, I wouldn't do a sed-script pass to actually change
existing users. I'd just change how the BUG() implementation itself
works. Not make it a direct WARN_ON(), but perhaps something like

 - use WARN_ON() with a global rate limiter (we do *not* want BUG
cascades, but re-enable the warning after a few minutes)

 - have some kernel command line option for the server people to allow
them to just force a reboot for it

Hmm?

Anybody want to play with it?

            Linus

Thread

BUG_ON() in workingset_node_shadows_dec() triggers Linus Torvalds <torvalds@linux-foundation.org> - 2016-10-04 06:10 +0200
  Re: BUG_ON() in workingset_node_shadows_dec() triggers Greg KH <greg@kroah.com> - 2016-10-04 10:20 +0200
  Re: BUG_ON() in workingset_node_shadows_dec() triggers Johannes Weiner <hannes@cmpxchg.org> - 2016-10-04 11:40 +0200
    Re: BUG_ON() in workingset_node_shadows_dec() triggers Linus Torvalds <torvalds@linux-foundation.org> - 2016-10-05 03:30 +0200
      Re: BUG_ON() in workingset_node_shadows_dec() triggers Johannes Weiner <hannes@cmpxchg.org> - 2016-10-05 11:30 +0200
        Re: BUG_ON() in workingset_node_shadows_dec() triggers Johannes Weiner <hannes@cmpxchg.org> - 2016-10-05 11:40 +0200
        Re: BUG_ON() in workingset_node_shadows_dec() triggers Jan Kara <jack@suse.cz> - 2016-10-05 12:50 +0200
        Re: BUG_ON() in workingset_node_shadows_dec() triggers Linus Torvalds <torvalds@linux-foundation.org> - 2016-10-05 18:20 +0200
          Re: [PATCH] checkpatch: extend BUG warning Linus Torvalds <torvalds@linux-foundation.org> - 2016-10-05 19:10 +0200
          [PATCH] checkpatch: extend BUG warning Joe Perches <joe@perches.com> - 2016-10-05 19:10 +0200
  Re: BUG_ON() in workingset_node_shadows_dec() triggers Paul Gortmaker <paul.gortmaker@windriver.com> - 2016-10-05 04:50 +0200
    Re: BUG_ON() in workingset_node_shadows_dec() triggers Linus Torvalds <torvalds@linux-foundation.org> - 2016-10-05 05:30 +0200
      Re: BUG_ON() in workingset_node_shadows_dec() triggers Willy Tarreau <w@1wt.eu> - 2016-10-05 07:50 +0200
        Re: BUG_ON() in workingset_node_shadows_dec() triggers Linus Torvalds <torvalds@linux-foundation.org> - 2016-10-05 18:00 +0200
          Re: BUG_ON() in workingset_node_shadows_dec() triggers Willy Tarreau <w@1wt.eu> - 2016-10-05 21:10 +0200
            Re: BUG_ON() in workingset_node_shadows_dec() triggers Linus Torvalds <torvalds@linux-foundation.org> - 2016-10-05 21:20 +0200
              Re: BUG_ON() in workingset_node_shadows_dec() triggers Willy Tarreau <w@1wt.eu> - 2016-10-05 23:20 +0200
              Re: BUG_ON() in workingset_node_shadows_dec() triggers Kees Cook <keescook@chromium.org> - 2016-10-05 23:20 +0200
                Re: BUG_ON() in workingset_node_shadows_dec() triggers Linus Torvalds <torvalds@linux-foundation.org> - 2016-10-05 23:50 +0200
                Re: BUG_ON() in workingset_node_shadows_dec() triggers Kees Cook <keescook@chromium.org> - 2016-10-06 00:20 +0200
                Re: BUG_ON() in workingset_node_shadows_dec() triggers Linus Torvalds <torvalds@linux-foundation.org> - 2016-10-06 00:40 +0200
                Re: BUG_ON() in workingset_node_shadows_dec() triggers Kees Cook <keescook@chromium.org> - 2016-10-07 00:10 +0200
                Re: BUG_ON() in workingset_node_shadows_dec() triggers Linus Torvalds <torvalds@linux-foundation.org> - 2016-10-07 00:30 +0200
                Re: BUG_ON() in workingset_node_shadows_dec() triggers Kees Cook <keescook@chromium.org> - 2016-10-07 01:10 +0200
                Re: BUG_ON() in workingset_node_shadows_dec() triggers Linus Torvalds <torvalds@linux-foundation.org> - 2016-10-07 02:00 +0200
                Re: BUG_ON() in workingset_node_shadows_dec() triggers Willy Tarreau <w@1wt.eu> - 2016-10-07 08:00 +0200
                Re: BUG_ON() in workingset_node_shadows_dec() triggers Kees Cook <keescook@chromium.org> - 2016-10-07 19:20 +0200
                Re: BUG_ON() in workingset_node_shadows_dec() triggers Linus Torvalds <torvalds@linux-foundation.org> - 2016-10-07 19:30 +0200
                Re: BUG_ON() in workingset_node_shadows_dec() triggers Kees Cook <keescook@chromium.org> - 2016-10-07 19:40 +0200
                Re: BUG_ON() in workingset_node_shadows_dec() triggers Willy Tarreau <w@1wt.eu> - 2016-10-07 20:30 +0200
      Re: BUG_ON() in workingset_node_shadows_dec() triggers Dave Chinner <david@fromorbit.com> - 2016-10-06 04:10 +0200
        Re: BUG_ON() in workingset_node_shadows_dec() triggers Linus Torvalds <torvalds@linux-foundation.org> - 2016-10-06 04:20 +0200

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