From: Matt Fleming <matt@console-pimps.org>
To: Guenter Roeck <linux@roeck-us.net>
Cc: Matt Fleming <matt.fleming@intel.com>,
linux-efi@vger.kernel.org, linux-kernel@vger.kernel.org,
Peter Zijlstra <peterz@infradead.org>
Subject: Re: [PATCH] firmware: Do not use WARN_ON(!spin_is_locked())
Date: Wed, 13 Aug 2014 15:18:36 +0100 [thread overview]
Message-ID: <20140813141836.GQ15082@console-pimps.org> (raw)
In-Reply-To: <1407729253-31341-1-git-send-email-linux@roeck-us.net>
On Sun, 10 Aug, at 08:54:13PM, Guenter Roeck wrote:
> spin_is_locked() always returns false for uniprocessor configurations,
> so do not use WARN_ON with it. WARN_ON_SMP() exists for that very
> purpose and must be used instead.
Good catch, though I worry that WARN_ON_SMP() doesn't seem to be a very
common pattern,
arch/x86/pci/i386.c: WARN_ON_SMP(!spin_is_locked(&pcibios_fwaddrmap_lock));
drivers/gpu/drm/drm_irq.c: WARN_ON_SMP(!spin_is_locked(&dev->event_lock));
include/asm-generic/bug.h: * WARN_ON_SMP() is for cases that the warning is either
include/asm-generic/bug.h: * WARN_ON_SMP(!zoot->bar);
include/asm-generic/bug.h: * For CONFIG_SMP, WARN_ON_SMP() should act the same as WARN_ON(),
include/asm-generic/bug.h: * if (WARN_ON_SMP(x)) returns true only when CONFIG_SMP is set
include/asm-generic/bug.h:# define WARN_ON_SMP(x) WARN_ON(x)
include/asm-generic/bug.h: * Use of ({0;}) because WARN_ON_SMP(x) may be used either as
include/asm-generic/bug.h:# define WARN_ON_SMP(x) ({0;})
kernel/futex.c: if (WARN_ON_SMP(!q->lock_ptr || !spin_is_locked(q->lock_ptr))
and people must want to do this kind of checking all the time.
How about lockdep_assert_held()? That seems to be much more popular.
--
Matt Fleming, Intel Open Source Technology Center
next prev parent reply other threads:[~2014-08-13 14:18 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-08-11 3:54 [PATCH] firmware: Do not use WARN_ON(!spin_is_locked()) Guenter Roeck
2014-08-13 14:18 ` Matt Fleming [this message]
2014-08-13 14:37 ` Guenter Roeck
2014-08-13 15:02 ` Matt Fleming
2014-08-13 23:31 ` Theodore Ts'o
2014-08-13 14:44 ` Peter Zijlstra
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