Re: [RFC PATCH 2/2] sched: sysctl: Panic on scheduling while atomic

From	Daniel Bristot de Oliveira <daolivei@redhat.com>
Newsgroups	linux.kernel
Subject	Re: [RFC PATCH 2/2] sched: sysctl: Panic on scheduling while atomic
Date	2016-06-01 15:40 +0200
Message-ID	<rFexj-yn-9@gated-at.bofh.it> (permalink)
References	<rEXd7-6Ej-1@gated-at.bofh.it> <rEXd7-6Ej-19@gated-at.bofh.it> <rFaWK-6IP-25@gated-at.bofh.it>
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On 06/01/2016 06:45 AM, Peter Zijlstra wrote:
> Do we really need more panic_on_* knobs? Can't we re-purpose
> panic_on_warn for this?

I think this case is very specific, specific enough to deserve its own
sysctl. But I see your point, and the possibilities I can see are:

1) convert the printk(KERN_ERR "BUG:...") to a WARN(1,"BUG:..."), but
this will hide all other information printed in the function, so -1 for
this option;

2) fire a WARN in the end of the function with a message like the
previous printk(); or

3) re-use the panic_on_warn variable to condition the panic,
or to force a WARN.

But, IMHO, I think these are not as polish as use a specific sysctl.

If you think that any of these options are better than what I propose,
I can cook a v2 with the best option :-).

-- Daniel

Thread

[RFC PATCH 0/2] sysctl: Panic on RCU stall and schedule while atomic Daniel Bristot de Oliveira <bristot@redhat.com> - 2016-05-31 21:10 +0200
  [RFC PATCH 1/2] rcu: sysctl: Panic on RCU Stall Daniel Bristot de Oliveira <bristot@redhat.com> - 2016-05-31 21:10 +0200
    Re: [RFC PATCH 1/2] rcu: sysctl: Panic on RCU Stall Josh Triplett <josh@joshtriplett.org> - 2016-05-31 21:20 +0200
      Re: [RFC PATCH 1/2] rcu: sysctl: Panic on RCU Stall Josh Triplett <josh@joshtriplett.org> - 2016-05-31 21:30 +0200
        Re: [RFC PATCH 1/2] rcu: sysctl: Panic on RCU Stall Daniel Bristot de Oliveira <daolivei@redhat.com> - 2016-06-01 00:50 +0200
          Re: [RFC PATCH 1/2] rcu: sysctl: Panic on RCU Stall "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> - 2016-06-01 04:40 +0200
  [RFC PATCH 2/2] sched: sysctl: Panic on scheduling while atomic Daniel Bristot de Oliveira <bristot@redhat.com> - 2016-05-31 21:10 +0200
    Re: [RFC PATCH 2/2] sched: sysctl: Panic on scheduling while atomic Josh Triplett <josh@joshtriplett.org> - 2016-05-31 21:30 +0200
    Re: [RFC PATCH 2/2] sched: sysctl: Panic on scheduling while atomic Peter Zijlstra <peterz@infradead.org> - 2016-06-01 11:50 +0200
      Re: [RFC PATCH 2/2] sched: sysctl: Panic on scheduling while atomic Daniel Bristot de Oliveira <daolivei@redhat.com> - 2016-06-01 15:40 +0200
  Re: [RFC PATCH 0/2] sysctl: Panic on RCU stall and schedule while  atomic Christian Borntraeger <borntraeger@de.ibm.com> - 2016-05-31 21:30 +0200

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