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From: Peter Zijlstra <peterz@infradead.org>
To: Waiman Long <longman@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>, Will Deacon <will.deacon@arm.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	linux-kernel@vger.kernel.org, x86@kernel.org,
	Arnd Bergmann <arnd@arndb.de>, Borislav Petkov <bp@alien8.de>,
	"H. Peter Anvin" <hpa@zytor.com>,
	Davidlohr Bueso <dave@stgolabs.net>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Tim Chen <tim.c.chen@linux.intel.com>
Subject: Re: [PATCH-tip v3 06/11] locking/rwsem: Enhance DEBUG_RWSEMS_WARN_ON() macro
Date: Wed, 3 Apr 2019 15:09:34 +0200	[thread overview]
Message-ID: <20190403130934.GH4038@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <1551380981-3113-7-git-send-email-longman@redhat.com>

On Thu, Feb 28, 2019 at 02:09:36PM -0500, Waiman Long wrote:
> diff --git a/kernel/locking/rwsem.h b/kernel/locking/rwsem.h
> index 1d8f722..c8fd3f1 100644
> --- a/kernel/locking/rwsem.h
> +++ b/kernel/locking/rwsem.h
> @@ -27,9 +27,13 @@
>  #define RWSEM_ANONYMOUSLY_OWNED	(1UL << 1)
>  
>  #ifdef CONFIG_DEBUG_RWSEMS
> -# define DEBUG_RWSEMS_WARN_ON(c)	DEBUG_LOCKS_WARN_ON(c)
> +# define DEBUG_RWSEMS_WARN_ON(c, sem)				\
> +	WARN_ONCE(c, "DEBUG_RWSEMS_WARN_ON(%s): count = 0x%lx, owner = 0x%lx, curr 0x%lx, list %sempty\n",\
> +		#c, atomic_long_read(&(sem)->count),		\
> +		(long)((sem)->owner), (long)current,		\
> +		list_empty(&(sem)->wait_list) ? "" : "not ")

This changes DEBUG_LOCKS_WARN_ON() to WARN_ONCE(), the difference being
that you now fail to kill lockdep on a rwsem error, which seems
unfortunate.

>  #else
> -# define DEBUG_RWSEMS_WARN_ON(c)
> +# define DEBUG_RWSEMS_WARN_ON(c, sem)
>  #endif

  reply	other threads:[~2019-04-03 13:09 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-02-28 19:09 [PATCH-tip v3 00/11] locking/rwsem: Rwsem rearchitecture part 1 Waiman Long
2019-02-28 19:09 ` [PATCH-tip v3 01/11] locking/rwsem: Relocate rwsem_down_read_failed() Waiman Long
2019-02-28 19:09 ` [PATCH-tip v3 02/11] locking/rwsem: Move owner setting code from rwsem.c to rwsem.h Waiman Long
2019-02-28 19:09 ` [PATCH-tip v3 03/11] locking/rwsem: Move rwsem internal function declarations to rwsem-xadd.h Waiman Long
2019-02-28 19:09 ` [PATCH-tip v3 04/11] locking/rwsem: Micro-optimize rwsem_try_read_lock_unqueued() Waiman Long
2019-02-28 19:09 ` [PATCH-tip v3 05/11] locking/rwsem: Add debug check for __down_read*() Waiman Long
2019-02-28 19:09 ` [PATCH-tip v3 06/11] locking/rwsem: Enhance DEBUG_RWSEMS_WARN_ON() macro Waiman Long
2019-04-03 13:09   ` Peter Zijlstra [this message]
2019-04-03 15:33     ` Waiman Long
2019-02-28 19:09 ` [PATCH-tip v3 07/11] locking/qspinlock_stat: Introduce a generic lockevent counting APIs Waiman Long
2019-02-28 19:09 ` [PATCH-tip v3 08/11] locking/lock_events: Make lock_events available for all archs & other locks Waiman Long
2019-02-28 19:09 ` [PATCH-tip v3 09/11] locking/lock_events: Don't show pvqspinlock events on bare metal Waiman Long
2019-02-28 19:09 ` [PATCH-tip v3 10/11] locking/rwsem: Enable lock event counting Waiman Long
2019-02-28 19:09 ` [PATCH-tip v3 11/11] locking/rwsem: Optimize rwsem structure for uncontended lock acquisition Waiman Long
2019-04-03 13:12   ` Peter Zijlstra
2019-04-03 15:35     ` Waiman Long

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