From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
To: Ingo Molnar <mingo@kernel.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>,
Thomas Gleixner <tglx@linutronix.de>, Ingo Molnar <mingo@elte.hu>,
"H. Peter Anvin" <hpa@zytor.com>,
Peter Zijlstra <peterz@infradead.org>,
linux-next@vger.kernel.org, linux-kernel@vger.kernel.org,
Andy Lutomirski <luto@kernel.org>
Subject: Re: linux-next: build failure after merge of the rcu tree
Date: Fri, 17 Jul 2015 14:33:36 -0700 [thread overview]
Message-ID: <20150717213336.GL3717@linux.vnet.ibm.com> (raw)
In-Reply-To: <20150717195131.GA27792@gmail.com>
On Fri, Jul 17, 2015 at 09:51:31PM +0200, Ingo Molnar wrote:
>
> * Paul E. McKenney <paulmck@linux.vnet.ibm.com> wrote:
>
> > And here is a prototype patch, which I intend to merge with the existing patch
> > that renames rcu_lockdep_assert() to RCU_LOCKDEP_WARN(). I will also queue a
> > revert of the patch below for 4.4.
> >
> > Thoughts?
> >
> > Thanx, Paul
> >
> > ------------------------------------------------------------------------
> >
> > diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
> > index 41c49b12fe6d..663d6e028c3d 100644
> > --- a/include/linux/rcupdate.h
> > +++ b/include/linux/rcupdate.h
> > @@ -536,9 +536,29 @@ static inline int rcu_read_lock_sched_held(void)
> >
> > #endif /* #else #ifdef CONFIG_DEBUG_LOCK_ALLOC */
> >
> > +/* Deprecate the rcu_lockdep_assert() macro. */
> > +static inline void __attribute((deprecated)) deprecate_rcu_lockdep_assert(void)
> > +{
> > +}
> > +
> > #ifdef CONFIG_PROVE_RCU
> >
> > /**
> > + * rcu_lockdep_assert - emit lockdep splat if specified condition not met
> > + * @c: condition to check
> > + * @s: informative message
> > + */
> > +#define rcu_lockdep_assert(c, s) \
> > + do { \
> > + static bool __section(.data.unlikely) __warned; \
> > + deprecate_rcu_lockdep_assert(); \
> > + if (debug_lockdep_rcu_enabled() && !__warned && !(c)) { \
> > + __warned = true; \
> > + lockdep_rcu_suspicious(__FILE__, __LINE__, s); \
> > + } \
>
> Btw., out of general macro paranoia I'd write such constructs as something like:
>
> if (!(c) && debug_lockdep_rcu_enabled() && !__warned) { \
>
> I.e. always evaluate 'c' even if debugging is off. This way if the construct is
> fed an expression with a side effect (bad idea!) then it still works regardless of
> whether the warning triggered already or not.
If you feel strongly about this, I will need to make lockdep_is_held()
be defined when lockdep is disabled. Easy enough to do, just thought
I should double-check.
> But this construct is OK too to me, so feel free to add my:
>
> Reviewed-by: Ingo Molnar <mingo@kernel.org>
Thank you!
Thanx, Paul
next prev parent reply other threads:[~2015-07-17 21:33 UTC|newest]
Thread overview: 152+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-07-16 3:14 linux-next: build failure after merge of the rcu tree Stephen Rothwell
2015-07-16 3:51 ` Paul E. McKenney
2015-07-16 5:50 ` Stephen Rothwell
2015-07-17 11:40 ` Ingo Molnar
2015-07-17 17:35 ` Paul E. McKenney
2015-07-17 18:53 ` Paul E. McKenney
2015-07-17 19:51 ` Ingo Molnar
2015-07-17 21:33 ` Paul E. McKenney [this message]
2015-07-18 2:40 ` Ingo Molnar
-- strict thread matches above, loose matches on Subject: below --
2024-01-24 4:17 Stephen Rothwell
2024-01-24 9:49 ` Jiri Wiesner
2024-01-24 12:12 ` Paul E. McKenney
2024-01-24 13:31 ` Jiri Wiesner
2024-01-24 14:20 ` Paul E. McKenney
2023-07-27 4:19 Stephen Rothwell
2023-07-27 14:08 ` Paul E. McKenney
2023-05-19 0:59 Stephen Rothwell
2023-05-19 2:12 ` Paul E. McKenney
2023-05-22 1:45 ` Stephen Rothwell
2023-05-22 14:57 ` Paul E. McKenney
2023-03-14 1:29 Stephen Rothwell
2023-03-14 4:43 ` Paul E. McKenney
2022-10-17 23:26 Stephen Rothwell
2022-10-18 10:43 ` Frederic Weisbecker
2022-10-18 14:57 ` Paul E. McKenney
2022-04-19 2:36 Stephen Rothwell
2022-04-19 3:31 ` Paul E. McKenney
2021-05-03 0:11 Stephen Rothwell
2021-05-03 16:25 ` Paul E. McKenney
2021-04-22 4:10 Stephen Rothwell
2021-04-22 16:36 ` Paul E. McKenney
2021-03-17 5:36 Stephen Rothwell
2021-03-17 14:23 ` Paul E. McKenney
2021-01-04 0:37 Stephen Rothwell
2021-01-04 12:56 ` Frederic Weisbecker
2020-12-04 8:25 Stephen Rothwell
2020-12-04 19:20 ` Paul E. McKenney
2020-12-06 21:39 ` Stephen Rothwell
2020-12-07 4:48 ` Paul E. McKenney
2020-12-07 8:59 ` Stephen Rothwell
2020-09-17 5:19 Stephen Rothwell
2020-09-17 22:01 ` Paul E. McKenney
2020-09-18 0:00 ` Stephen Rothwell
2020-09-08 5:38 Stephen Rothwell
2020-09-08 13:54 ` Paul E. McKenney
2020-08-18 1:43 Stephen Rothwell
2020-08-18 14:08 ` Paul E. McKenney
2020-06-25 2:57 Stephen Rothwell
2020-06-25 3:45 ` Paul E. McKenney
2020-05-28 9:05 Stephen Rothwell
2020-05-28 16:33 ` Paul E. McKenney
2020-05-28 21:03 ` Paul E. McKenney
2020-04-05 1:49 Stephen Rothwell
2020-04-05 3:10 ` Paul E. McKenney
2020-01-17 3:07 Stephen Rothwell
2019-12-12 2:45 Stephen Rothwell
2019-12-12 4:07 ` Paul E. McKenney
2019-12-12 4:26 ` Stephen Rothwell
2019-12-12 4:41 ` Paul E. McKenney
2020-01-17 3:09 ` Stephen Rothwell
2019-08-13 7:57 Stephen Rothwell
2019-08-13 15:31 ` Paul E. McKenney
2019-08-12 6:12 Stephen Rothwell
2019-08-12 16:19 ` Paul E. McKenney
2019-08-13 5:25 ` Stephen Rothwell
2019-08-13 14:38 ` Paul E. McKenney
2017-09-04 4:50 Stephen Rothwell
2017-09-04 16:39 ` Paul E. McKenney
2017-08-28 4:25 Stephen Rothwell
2017-08-28 17:50 ` Paul E. McKenney
2017-08-11 4:43 Stephen Rothwell
2017-08-11 4:54 ` Paul E. McKenney
2017-08-11 9:14 ` Peter Zijlstra
2017-08-11 14:39 ` Paul E. McKenney
2017-08-11 14:45 ` Peter Zijlstra
2017-08-11 14:41 ` Peter Zijlstra
2017-08-11 20:12 ` Paul E. McKenney
2017-05-29 6:02 Stephen Rothwell
2017-05-29 21:15 ` Paul E. McKenney
2017-05-30 1:40 ` Stephen Rothwell
2017-05-30 1:54 ` Joe Perches
2017-05-30 2:14 ` Paul E. McKenney
2017-05-30 2:20 ` Joe Perches
2017-05-30 3:13 ` Stephen Rothwell
2017-05-30 4:10 ` Michael Ellerman
2017-06-02 17:51 ` Paul E. McKenney
2017-04-20 5:36 Stephen Rothwell
2017-04-20 14:23 ` Paul E. McKenney
2017-04-19 3:50 Stephen Rothwell
2017-04-19 4:06 ` Paul E. McKenney
2017-04-19 5:45 ` Stephen Rothwell
2017-03-08 1:16 Stephen Rothwell
2017-03-08 10:13 ` Daniel Vetter
2017-03-08 17:40 ` Paul E. McKenney
2017-01-19 3:34 Stephen Rothwell
2017-01-19 21:54 ` Paul McKenney
2017-02-13 2:21 ` Stephen Rothwell
2017-02-13 4:37 ` Paul E. McKenney
2017-02-13 6:43 ` Stephen Rothwell
2017-03-08 1:16 ` Stephen Rothwell
2017-03-08 1:37 ` Paul E. McKenney
2017-03-08 18:05 ` Paul E. McKenney
2016-05-02 4:37 Stephen Rothwell
2016-05-02 11:06 ` Paul E. McKenney
2016-02-01 2:55 Stephen Rothwell
2016-02-01 9:53 ` Paul E. McKenney
2016-01-07 8:57 Stephen Rothwell
2016-01-07 18:02 ` Paul E. McKenney
2016-01-07 20:19 ` Stephen Rothwell
2016-01-07 20:52 ` Paul E. McKenney
2016-01-08 1:37 ` Boqun Feng
2016-01-08 3:41 ` Paul E. McKenney
2016-01-08 4:08 ` Stephen Rothwell
2016-01-08 4:48 ` Paul E. McKenney
2016-01-08 4:54 ` Boqun Feng
2016-01-08 15:53 ` Paul E. McKenney
2016-01-08 15:57 ` Tejun Heo
2016-01-08 16:18 ` Paul E. McKenney
2016-01-08 15:58 ` Boqun Feng
2016-01-08 4:10 ` Stephen Rothwell
2015-09-01 3:50 Stephen Rothwell
2015-09-01 7:49 ` Paul E. McKenney
2015-09-02 3:58 ` Stephen Rothwell
2015-09-02 5:26 ` Paul E. McKenney
2015-09-02 6:40 ` Davidlohr Bueso
2015-09-02 7:14 ` Paul E. McKenney
2015-09-02 7:29 ` Ingo Molnar
2015-09-02 8:34 ` Paul E. McKenney
2015-04-13 10:39 Stephen Rothwell
2015-04-13 11:06 ` Borislav Petkov
2015-04-13 11:34 ` Ingo Molnar
2015-04-13 12:40 ` Paul E. McKenney
2015-02-27 2:18 Stephen Rothwell
2015-02-27 5:59 ` Paul E. McKenney
2014-12-26 7:51 Stephen Rothwell
2014-12-26 16:54 ` Paul E. McKenney
2014-12-27 16:24 ` Pranith Kumar
2014-12-27 17:20 ` Pranith Kumar
2014-12-31 1:45 ` Paul E. McKenney
2014-12-12 6:12 Stephen Rothwell
2014-12-12 17:23 ` Paul E. McKenney
2014-12-10 8:09 Stephen Rothwell
2014-12-10 15:03 ` Pranith Kumar
2014-12-10 15:18 ` Paul E. McKenney
2014-12-09 11:42 Stephen Rothwell
2014-12-09 14:07 ` Paul E. McKenney
2012-04-16 4:11 Stephen Rothwell
2012-04-16 17:02 ` Paul E. McKenney
2010-09-17 2:42 Stephen Rothwell
2010-09-17 4:39 ` David Miller
2010-09-17 5:34 ` Eric Dumazet
2010-09-17 23:17 ` Paul E. McKenney
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