From: Mathieu Desnoyers <compudj@krystal.dyndns.org>
To: Andrew Morton <akpm@osdl.org>
Cc: Greg Kroah-Hartman <gregkh@suse.de>,
Richard J Moore <richardj_moore@uk.ibm.com>,
linux-kernel@vger.kernel.org,
"Martin J. Bligh" <mbligh@mbligh.org>,
Christoph Hellwig <hch@infradead.org>,
Douglas Niehaus <niehaus@eecs.ku.edu>,
Ingo Molnar <mingo@redhat.com>,
ltt-dev@shafik.org, systemtap@sources.redhat.com,
Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [PATCH] minimize lockdep_on/off side-effect
Date: Wed, 24 Jan 2007 18:01:00 -0000 [thread overview]
Message-ID: <20070124175557.GA160@Krystal> (raw)
In-Reply-To: <20070124172445.GA1145@Krystal>
Minimize lockdep_on/off side-effect on irq tracing in vprintk by using
raw_local_irq_save/restore _around_ lockdep_off/on().
It applies on the previous patch. It has the advantage of not losing the IRQ
events coming between the lockdep disabling and the irq disabling.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -530,8 +530,8 @@ asmlinkage int vprintk(const char *fmt, va_list args)
zap_locks();
/* This stops the holder of console_sem just where we want him */
+ raw_local_irq_save(flags);
lockdep_off();
- local_irq_save(flags);
spin_lock(&logbuf_lock);
printk_cpu = smp_processor_id();
@@ -640,8 +640,8 @@ asmlinkage int vprintk(const char *fmt, va_list args)
console_locked = 0;
up(&console_sem);
}
- local_irq_restore(flags);
lockdep_on();
+ raw_local_irq_restore(flags);
} else {
/*
* Someone else owns the drivers. We drop the spinlock, which
@@ -650,8 +650,8 @@ asmlinkage int vprintk(const char *fmt, va_list args)
*/
printk_cpu = UINT_MAX;
spin_unlock(&logbuf_lock);
- local_irq_restore(flags);
lockdep_on();
+ raw_local_irq_restore(flags);
}
preempt_enable();
--
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prev parent reply other threads:[~2007-01-24 18:01 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-12-21 0:01 [PATCH 0/4] Linux Kernel Markers Mathieu Desnoyers
2006-12-21 0:01 ` [PATCH 2/4] Linux Kernel Markers : kconfig menus Mathieu Desnoyers
2006-12-21 0:03 ` [PATCH 3/4] Linux Kernel Markers : i386 optimisation Mathieu Desnoyers
2006-12-21 0:04 ` [PATCH 4/4] Linux Kernel Markers : powerpc optimisation Mathieu Desnoyers
2006-12-21 0:07 ` [PATCH 1/4] Linux Kernel Markers : Architecture agnostic code Mathieu Desnoyers
2007-01-13 1:33 ` [PATCH 0/4] Linux Kernel Markers Richard J Moore
2007-01-13 5:51 ` Mathieu Desnoyers
2007-01-16 17:47 ` [PATCH 0/4 update] Linux Kernel Markers - i386 : pIII erratum 49 : XMC Mathieu Desnoyers
2007-01-16 18:35 ` Frank Ch. Eigler
2007-01-16 21:28 ` [PATCH 0/4 update] kprobes and traps Mathieu Desnoyers
2007-01-17 12:26 ` S. P. Prasanna
2007-01-16 18:01 ` [PATCH 2/2] lockdep reentrancy Mathieu Desnoyers
2007-01-24 4:30 ` Andrew Morton
2007-01-24 17:05 ` Mathieu Desnoyers
2007-01-16 18:06 ` [PATCH 1/2] lockdep missing barrier() Mathieu Desnoyers
2007-01-24 4:28 ` Andrew Morton
2007-01-24 17:02 ` Mathieu Desnoyers
2007-01-24 17:30 ` [PATCH] order of lockdep off/on in vprintk() should be changed Mathieu Desnoyers
2007-01-24 18:01 ` Mathieu Desnoyers [this message]
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