From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964804AbWJ3NHO (ORCPT ); Mon, 30 Oct 2006 08:07:14 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964855AbWJ3NHO (ORCPT ); Mon, 30 Oct 2006 08:07:14 -0500 Received: from mx.go2.pl ([193.17.41.41]:53413 "EHLO poczta.o2.pl") by vger.kernel.org with ESMTP id S964804AbWJ3NHM (ORCPT ); Mon, 30 Oct 2006 08:07:12 -0500 Date: Mon, 30 Oct 2006 14:12:41 +0100 From: Jarek Poplawski To: Peter Zijlstra Cc: linux-kernel@vger.kernel.org, Arjan van de Ven , Ingo Molnar , Jiri Kosina , Marcel Holtmann , David Woodhouse Subject: Re: [PATCH 1/2] lockdep: spin_lock_irqsave_nested() Message-ID: <20061030131241.GA1657@ff.dom.local> Mail-Followup-To: Jarek Poplawski , Peter Zijlstra , linux-kernel@vger.kernel.org, Arjan van de Ven , Ingo Molnar , Jiri Kosina , Marcel Holtmann , David Woodhouse Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1162199005.24143.169.camel@taijtu> User-Agent: Mutt/1.4.2.2i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Here are some doubts... Jarek P. On 30-10-2006 10:03, Peter Zijlstra wrote: > From: Arjan van de Ven > Subject: spin_lock_irqsave_nested() > > Introduce spin_lock_irqsave_nested(); implementation from: > http://lkml.org/lkml/2006/6/1/122 > Patch from: > http://lkml.org/lkml/2006/9/13/258 > > Signed-off-by: Arjan van de Ven > Signed-off-by: Jiri Kosina > Signed-off-by: Peter Zijlstra > --- > include/linux/spinlock.h | 5 +++++ > include/linux/spinlock_api_smp.h | 2 ++ > include/linux/spinlock_api_up.h | 1 + > kernel/spinlock.c | 21 +++++++++++++++++++++ > 4 files changed, 29 insertions(+) > > Index: linux-2.6/include/linux/spinlock_api_smp.h > =================================================================== > --- linux-2.6.orig/include/linux/spinlock_api_smp.h > +++ linux-2.6/include/linux/spinlock_api_smp.h > @@ -32,6 +32,8 @@ void __lockfunc _read_lock_irq(rwlock_t > void __lockfunc _write_lock_irq(rwlock_t *lock) __acquires(lock); > unsigned long __lockfunc _spin_lock_irqsave(spinlock_t *lock) > __acquires(lock); > +unsigned long __lockfunc _spin_lock_irqsave_nested(spinlock_t *lock, int subclass) > + __acquires(spinlock_t); According to neighbours rather: + __acquires(lock); > unsigned long __lockfunc _read_lock_irqsave(rwlock_t *lock) > __acquires(lock); > unsigned long __lockfunc _write_lock_irqsave(rwlock_t *lock) > Index: linux-2.6/include/linux/spinlock_api_up.h > =================================================================== > --- linux-2.6.orig/include/linux/spinlock_api_up.h > +++ linux-2.6/include/linux/spinlock_api_up.h > @@ -59,6 +59,7 @@ > #define _read_lock_irq(lock) __LOCK_IRQ(lock) > #define _write_lock_irq(lock) __LOCK_IRQ(lock) > #define _spin_lock_irqsave(lock, flags) __LOCK_IRQSAVE(lock, flags) > +#define _spin_lock_irqsave_nested(lock, flags, subclass) __LOCK_IRQSAVE(lock, flags, subclass) Is __LOCK_IRQSAVE() with 3 args defined? > #define _read_lock_irqsave(lock, flags) __LOCK_IRQSAVE(lock, flags) > #define _write_lock_irqsave(lock, flags) __LOCK_IRQSAVE(lock, flags) > #define _spin_trylock(lock) ({ __LOCK(lock); 1; }) > Index: linux-2.6/include/linux/spinlock.h > =================================================================== > --- linux-2.6.orig/include/linux/spinlock.h > +++ linux-2.6/include/linux/spinlock.h > @@ -186,6 +186,11 @@ do { \ > #define spin_lock_irqsave(lock, flags) flags = _spin_lock_irqsave(lock) > #define read_lock_irqsave(lock, flags) flags = _read_lock_irqsave(lock) > #define write_lock_irqsave(lock, flags) flags = _write_lock_irqsave(lock) > +#ifdef CONFIG_DEBUG_LOCK_ALLOC > +#define spin_lock_irqsave_nested(lock, flags, subclass) flags = _spin_lock_irqsave_nested(lock, subclass) > +#else > +#define spin_lock_irqsave_nested(lock, flags, subclass) flags = _spin_lock_irqsave(lock) > +#endif > #else Plus for api_up: +#ifdef CONFIG_DEBUG_LOCK_ALLOC +#define spin_lock_irqsave_nested(lock, flags, subclass) _spin_lock_irqsave_nested(lock, flags, subclass) +#else +#define spin_lock_irqsave_nested(lock, flags, subclass) _spin_lock_irqsave(lock, flags) +#endif > #define spin_lock_irqsave(lock, flags) _spin_lock_irqsave(lock, flags) > #define read_lock_irqsave(lock, flags) _read_lock_irqsave(lock, flags) > Index: linux-2.6/kernel/spinlock.c > =================================================================== > --- linux-2.6.orig/kernel/spinlock.c > +++ linux-2.6/kernel/spinlock.c > @@ -293,6 +293,27 @@ void __lockfunc _spin_lock_nested(spinlo > } > > EXPORT_SYMBOL(_spin_lock_nested); > +unsigned long __lockfunc _spin_lock_irqsave_nested(spinlock_t *lock, int subclass) > +{ > + unsigned long flags; > + > + local_irq_save(flags); > + preempt_disable(); > + spin_acquire(&lock->dep_map, subclass, 0, _RET_IP_); > + /* > + * On lockdep we dont want the hand-coded irq-enable of > + * _raw_spin_lock_flags() code, because lockdep assumes > + * that interrupts are not re-enabled during lock-acquire: > + */ > +#ifdef CONFIG_PROVE_SPIN_LOCKING > + _raw_spin_lock(lock); > +#else > + _raw_spin_lock_flags(lock, &flags); > +#endif > + return flags; > +} > + > +EXPORT_SYMBOL(_spin_lock_irqsave_nested); > > #endif > > Shouldn't this _nested locks be considered in: #else /* CONFIG_PREEMPT: */ part?