lkml.org 
[lkml]   [2007]   [Jan]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
SubjectRe: [PATCH] minimize lockdep_on/off side-effect
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();
--
OpenPGP public key: http://krystal.dyndns.org:8080/key/compudj.gpg
Key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
\
 
 \ /
  Last update: 2007-01-24 19:43    [W:0.083 / U:0.016 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site