Re: DEBUG_LOCKS_WARN_ON(in_interrupt()) triggering in socket code

From	Michal Kubecek <mkubecek@suse.cz>
Newsgroups	linux.kernel
Subject	Re: DEBUG_LOCKS_WARN_ON(in_interrupt()) triggering in socket code
Date	2015-08-21 16:10 +0200
Message-ID	<pZVb4-5RQ-25@gated-at.bofh.it> (permalink)
References	<pZm3E-5ms-7@gated-at.bofh.it> <pZQEq-7Jq-13@gated-at.bofh.it> <pZURI-5fy-39@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On Fri, Aug 21, 2015 at 03:42:33PM +0200, Jason A. Donenfeld wrote:
> Ahhh, interesting, so it turns out you can't do a number of things
> with a read_lock_bh held, because it increases the softirq count.
> Mystery solved.

You must not do anything that can sleep (like taking a mutex) while
holding a rwlock (even for reading) as someone else could call
write_lock() on the same rwlock on the same CPU in the meantime and
would end up spinning indefinitely while waiting for you to release it.

                                                        Michal Kubecek
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DEBUG_LOCKS_WARN_ON(in_interrupt()) triggering in socket code "Jason A. Donenfeld" <Jason@zx2c4.com> - 2015-08-20 02:40 +0200
  Re: DEBUG_LOCKS_WARN_ON(in_interrupt()) triggering in socket code "Jason A. Donenfeld" <Jason@zx2c4.com> - 2015-08-21 11:20 +0200
    Re: DEBUG_LOCKS_WARN_ON(in_interrupt()) triggering in socket code "Jason A. Donenfeld" <Jason@zx2c4.com> - 2015-08-21 15:50 +0200
      Re: DEBUG_LOCKS_WARN_ON(in_interrupt()) triggering in socket code Michal Kubecek <mkubecek@suse.cz> - 2015-08-21 16:10 +0200

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