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* [PATCH 0/4] printk: Remove lockdep_off() and wakeups -v3
@ 2011-06-21 15:17 Peter Zijlstra
  2011-06-21 15:17 ` [PATCH 1/4] printk: Release console_sem after logbuf_lock Peter Zijlstra
                   ` (4 more replies)
  0 siblings, 5 replies; 10+ messages in thread
From: Peter Zijlstra @ 2011-06-21 15:17 UTC (permalink / raw)
  To: Linus Torvalds, Ingo Molnar, Thomas Gleixner; +Cc: linux-kernel, akpm, efault

Last iteration of the printk() rework which removes the lockdep_off() hackery
and removes the need for printk() to issue wakeups, thereby increasing
reliability from variuos contexts.

Patch 0b5e1c5255 from -tip needs to be reverted (or better dropped), due
us discovering why doing up() under logbuf_lock was important -- thanks 
Andrew, Ingo!

This series was tested on a lockdep enabled kernel with the below hack
included, which generated a nice splat.

---
 kernel/printk.c |    5 +++++
 1 file changed, 5 insertions(+)

Index: linux-2.6/kernel/printk.c
===================================================================
--- linux-2.6.orig/kernel/printk.c
+++ linux-2.6/kernel/printk.c
@@ -930,6 +930,11 @@ asmlinkage int vprintk(const char *fmt, 
 	spin_lock(&logbuf_lock);
 	printk_cpu = this_cpu;
 
+	if (panic_timeout) {
+		panic_timeout = 0;
+		local_irq_enable();
+	}
+
 	if (recursion_bug) {
 		recursion_bug = 0;
 		strcpy(printk_buf, recursion_bug_msg);


^ permalink raw reply	[flat|nested] 10+ messages in thread

end of thread, other threads:[~2011-06-22 15:13 UTC | newest]

Thread overview: 10+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2011-06-21 15:17 [PATCH 0/4] printk: Remove lockdep_off() and wakeups -v3 Peter Zijlstra
2011-06-21 15:17 ` [PATCH 1/4] printk: Release console_sem after logbuf_lock Peter Zijlstra
2011-06-21 15:17 ` [PATCH 2/4] lockdep: Fix trace_{soft,hard}irqs_{on,off}() recursion Peter Zijlstra
2011-06-22 15:13   ` [tip:core/printk] lockdep: Fix trace_[soft,hard]irqs_[on,off]() recursion tip-bot for Peter Zijlstra
2011-06-21 15:17 ` [PATCH 3/4] printk, lockdep: Remove lockdep_off() usage Peter Zijlstra
2011-06-21 15:17 ` [PATCH 4/4] printk: Avoid all wakeups from printk Peter Zijlstra
2011-06-22  9:20 ` [PATCH 0/4] printk: Remove lockdep_off() and wakeups -v3 Peter Zijlstra
2011-06-22 11:50   ` Ingo Molnar
2011-06-22 13:44     ` Peter Zijlstra
2011-06-22 14:22   ` [tip:core/printk] printk: Fix console_sem vs logbuf_lock unlock race tip-bot for Peter Zijlstra

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