All of lore.kernel.org
 help / color / mirror / Atom feed
* [PATCH]: use spin_lock_irqsave in try_one_irq()
@ 2009-11-03 13:45 Prarit Bhargava
  2009-11-03 14:58 ` Yong Zhang
  0 siblings, 1 reply; 8+ messages in thread
From: Prarit Bhargava @ 2009-11-03 13:45 UTC (permalink / raw)
  To: linux-kernel, ebiederm, akpm; +Cc: Prarit Bhargava

(Prarit: Second try at this one, not sure if this made it to LKML or not.
 Sending to a wider audience this time)

Booting 2.6.32-rc5 on some IBM systems results in

Disabling IRQ #19

=================================
[ INFO: inconsistent lock state ]
2.6.32-rc5 #1
---------------------------------
inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage.
swapper/0 [HC0[0]:SC1[1]:HE1:SE0] takes:
 (&irq_desc_lock_class){?.-...}, at: [<ffffffff810c264e>] try_one_irq+0x32/0x138
{IN-HARDIRQ-W} state was registered at:
  [<ffffffff81095160>] __lock_acquire+0x2fc/0xd5d
  [<ffffffff81095cb4>] lock_acquire+0xf3/0x12d
  [<ffffffff814cdadd>] _spin_lock+0x40/0x89
  [<ffffffff810c3389>] handle_level_irq+0x30/0x105
  [<ffffffff81014e0e>] handle_irq+0x95/0xb7
  [<ffffffff810141bd>] do_IRQ+0x6a/0xe0
  [<ffffffff81012813>] ret_from_intr+0x0/0x16
irq event stamp: 195096
hardirqs last  enabled at (195096): [<ffffffff814cd7f7>] _spin_unlock_irq+0x3a/0x5c
hardirqs last disabled at (195095): [<ffffffff814cdbdd>] _spin_lock_irq+0x29/0x95
softirqs last  enabled at (195088): [<ffffffff81068c92>] __do_softirq+0x1c1/0x1ef
softirqs last disabled at (195093): [<ffffffff8101304c>] call_softirq+0x1c/0x30
 
other info that might help us debug this:
1 lock held by swapper/0:
 #0:  (kernel/irq/spurious.c:21){+.-...}, at: [<ffffffff81070cf2>] run_timer_softirq+0x1a9/0x315

stack backtrace:
Pid: 0, comm: swapper Not tainted 2.6.32-rc5 #1
Call Trace:
 <IRQ>  [<ffffffff81093e94>] valid_state+0x187/0x1ae
 [<ffffffff81096c7b>] ? check_usage_backwards+0x0/0xa3
 [<ffffffff81093fe4>] mark_lock+0x129/0x253
 [<ffffffff810951d4>] __lock_acquire+0x370/0xd5d
 [<ffffffff810c264e>] ? try_one_irq+0x32/0x138
 [<ffffffff8109329d>] ? save_trace+0x4e/0xcd
 [<ffffffff81095cb4>] lock_acquire+0xf3/0x12d
 [<ffffffff810c264e>] ? try_one_irq+0x32/0x138
 [<ffffffff81070cf2>] ? run_timer_softirq+0x1a9/0x315
 [<ffffffff810c264e>] ? try_one_irq+0x32/0x138
 [<ffffffff814cdadd>] _spin_lock+0x40/0x89
 [<ffffffff810c264e>] ? try_one_irq+0x32/0x138
 [<ffffffff810c264e>] try_one_irq+0x32/0x138
 [<ffffffff810c2795>] poll_all_shared_irqs+0x41/0x6d
 [<ffffffff810c27dd>] poll_spurious_irqs+0x1c/0x49
 [<ffffffff81070d82>] run_timer_softirq+0x239/0x315
 [<ffffffff81070cf2>] ? run_timer_softirq+0x1a9/0x315
 [<ffffffff810c27c1>] ? poll_spurious_irqs+0x0/0x49
 [<ffffffff81068bd3>] __do_softirq+0x102/0x1ef
 [<ffffffff8108eccf>] ? tick_dev_program_event+0x46/0xcc
 [<ffffffff8101304c>] call_softirq+0x1c/0x30
 [<ffffffff81014b65>] do_softirq+0x59/0xca
 [<ffffffff810686ad>] irq_exit+0x58/0xae
 [<ffffffff81029b84>] smp_apic_timer_interrupt+0x94/0xba
 [<ffffffff81012a33>] apic_timer_interrupt+0x13/0x20
 <EOI>  [<ffffffff8101a7b5>] ? mwait_idle+0x8c/0xb5
 [<ffffffff8101a7ac>] ? mwait_idle+0x83/0xb5
 [<ffffffff81010e55>] ? cpu_idle+0xbe/0x100
 [<ffffffff814c4270>] ? start_secondary+0x219/0x270

This happens because the &desc->lock is taken with spin_lock_irqsave and
just a spin_lock.  In the try_one_irq(), this lock really should be a
spin_lock_irqsave().

I have not yet narrowed down the reason for the spurious interrupt (although
I suspect it maybe to do with the radeon driver).

Successfully tested by me.

Signed-off-by: Prarit Bhargava <prarit@redhat.com>

--- linux-2.6.31.x86_64.orig/kernel/irq/spurious.c	2009-09-09 18:13:59.000000000 -0400
+++ linux-2.6.31.x86_64/kernel/irq/spurious.c	2009-10-26 10:55:56.709845786 -0400
@@ -27,8 +27,9 @@ static int try_one_irq(int irq, struct i
 {
 	struct irqaction *action;
 	int ok = 0, work = 0;
+	unsigned long flags;
 
-	spin_lock(&desc->lock);
+	spin_lock_irqsave(&desc->lock, flags);
 	/* Already running on another processor */
 	if (desc->status & IRQ_INPROGRESS) {
 		/*
@@ -37,13 +38,13 @@ static int try_one_irq(int irq, struct i
 		 */
 		if (desc->action && (desc->action->flags & IRQF_SHARED))
 			desc->status |= IRQ_PENDING;
-		spin_unlock(&desc->lock);
+		spin_unlock_irqrestore(&desc->lock, flags);
 		return ok;
 	}
 	/* Honour the normal IRQ locking */
 	desc->status |= IRQ_INPROGRESS;
 	action = desc->action;
-	spin_unlock(&desc->lock);
+	spin_unlock_irqrestore(&desc->lock, flags);
 
 	while (action) {
 		/* Only shared IRQ handlers are safe to call */
@@ -56,7 +57,7 @@ static int try_one_irq(int irq, struct i
 	}
 	local_irq_disable();
 	/* Now clean up the flags */
-	spin_lock(&desc->lock);
+	spin_lock_irqsave(&desc->lock, flags);
 	action = desc->action;
 
 	/*
@@ -68,9 +69,9 @@ static int try_one_irq(int irq, struct i
 		 * Perform real IRQ processing for the IRQ we deferred
 		 */
 		work = 1;
-		spin_unlock(&desc->lock);
+		spin_unlock_irqrestore(&desc->lock, flags);
 		handle_IRQ_event(irq, action);
-		spin_lock(&desc->lock);
+		spin_lock_irqsave(&desc->lock, flags);
 		desc->status &= ~IRQ_PENDING;
 	}
 	desc->status &= ~IRQ_INPROGRESS;
@@ -80,7 +81,7 @@ static int try_one_irq(int irq, struct i
 	 */
 	if (work && desc->chip && desc->chip->end)
 		desc->chip->end(irq);
-	spin_unlock(&desc->lock);
+	spin_unlock_irqrestore(&desc->lock, flags);
 
 	return ok;
 }

^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH]: use spin_lock_irqsave in try_one_irq()
  2009-11-03 13:45 [PATCH]: use spin_lock_irqsave in try_one_irq() Prarit Bhargava
@ 2009-11-03 14:58 ` Yong Zhang
  2009-11-03 15:03   ` Prarit Bhargava
  2009-11-04  9:18   ` Thomas Gleixner
  0 siblings, 2 replies; 8+ messages in thread
From: Yong Zhang @ 2009-11-03 14:58 UTC (permalink / raw)
  To: Prarit Bhargava
  Cc: linux-kernel, ebiederm, akpm, Ingo Molnar, Thomas Gleixner

> This happens because the &desc->lock is taken with spin_lock_irqsave and
> just a spin_lock.  In the try_one_irq(), this lock really should be a
> spin_lock_irqsave().
>

Cc'ed Ingo and Thomas.

The reason is that try_one_irq() is called both from hardirq context and softirq
context. And by default the timer handler poll_all_shared_irqs() is
called with irq enabled.
Then the two usage will cause inconsistent.

So I think the following patch is also workable to you.

diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c
index 114e704..11affbc 100644
--- a/kernel/irq/spurious.c
+++ b/kernel/irq/spurious.c
@@ -111,6 +111,7 @@ static void poll_all_shared_irqs(void)

 	for_each_irq_desc(i, desc) {
 		unsigned int status;
+		unsigned long flags;

 		if (!i)
 			 continue;
@@ -121,7 +122,9 @@ static void poll_all_shared_irqs(void)
 		if (!(status & IRQ_SPURIOUS_DISABLED))
 			continue;

+		local_irq_save(flags);
 		try_one_irq(i, desc);
+		local_irq_restore(flags);
 	}
 }

> I have not yet narrowed down the reason for the spurious interrupt (although
> I suspect it maybe to do with the radeon driver).
>
> Successfully tested by me.
>
> Signed-off-by: Prarit Bhargava <prarit@redhat.com>
>
> --- linux-2.6.31.x86_64.orig/kernel/irq/spurious.c      2009-09-09 18:13:59.000000000 -0400
> +++ linux-2.6.31.x86_64/kernel/irq/spurious.c   2009-10-26 10:55:56.709845786 -0400
> @@ -27,8 +27,9 @@ static int try_one_irq(int irq, struct i
>  {
>        struct irqaction *action;
>        int ok = 0, work = 0;
> +       unsigned long flags;
>
> -       spin_lock(&desc->lock);
> +       spin_lock_irqsave(&desc->lock, flags);
>        /* Already running on another processor */
>        if (desc->status & IRQ_INPROGRESS) {
>                /*
> @@ -37,13 +38,13 @@ static int try_one_irq(int irq, struct i
>                 */
>                if (desc->action && (desc->action->flags & IRQF_SHARED))
>                        desc->status |= IRQ_PENDING;
> -               spin_unlock(&desc->lock);
> +               spin_unlock_irqrestore(&desc->lock, flags);
>                return ok;
>        }
>        /* Honour the normal IRQ locking */
>        desc->status |= IRQ_INPROGRESS;
>        action = desc->action;
> -       spin_unlock(&desc->lock);
> +       spin_unlock_irqrestore(&desc->lock, flags);
>
>        while (action) {
>                /* Only shared IRQ handlers are safe to call */
> @@ -56,7 +57,7 @@ static int try_one_irq(int irq, struct i
>        }
>        local_irq_disable();
>        /* Now clean up the flags */
> -       spin_lock(&desc->lock);
> +       spin_lock_irqsave(&desc->lock, flags);
>        action = desc->action;
>
>        /*
> @@ -68,9 +69,9 @@ static int try_one_irq(int irq, struct i
>                 * Perform real IRQ processing for the IRQ we deferred
>                 */
>                work = 1;
> -               spin_unlock(&desc->lock);
> +               spin_unlock_irqrestore(&desc->lock, flags);
>                handle_IRQ_event(irq, action);
> -               spin_lock(&desc->lock);
> +               spin_lock_irqsave(&desc->lock, flags);
>                desc->status &= ~IRQ_PENDING;
>        }
>        desc->status &= ~IRQ_INPROGRESS;
> @@ -80,7 +81,7 @@ static int try_one_irq(int irq, struct i
>         */
>        if (work && desc->chip && desc->chip->end)
>                desc->chip->end(irq);
> -       spin_unlock(&desc->lock);
> +       spin_unlock_irqrestore(&desc->lock, flags);
>
>        return ok;
>  }
> --
> 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/
>

^ permalink raw reply related	[flat|nested] 8+ messages in thread

* Re: [PATCH]: use spin_lock_irqsave in try_one_irq()
  2009-11-03 14:58 ` Yong Zhang
@ 2009-11-03 15:03   ` Prarit Bhargava
  2009-11-04  9:18   ` Thomas Gleixner
  1 sibling, 0 replies; 8+ messages in thread
From: Prarit Bhargava @ 2009-11-03 15:03 UTC (permalink / raw)
  To: Yong Zhang; +Cc: linux-kernel, ebiederm, akpm, Ingo Molnar, Thomas Gleixner



Yong Zhang wrote:
>> This happens because the &desc->lock is taken with spin_lock_irqsave and
>> just a spin_lock.  In the try_one_irq(), this lock really should be a
>> spin_lock_irqsave().
>>
>>     
>
> Cc'ed Ingo and Thomas.
>
> The reason is that try_one_irq() is called both from hardirq context and softirq
> context. And by default the timer handler poll_all_shared_irqs() is
> called with irq enabled.
> Then the two usage will cause inconsistent.
>
> So I think the following patch is also workable to you.
>   

Ah, okay.  I will retest and get back to you ...

P.

^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH]: use spin_lock_irqsave in try_one_irq()
  2009-11-03 14:58 ` Yong Zhang
  2009-11-03 15:03   ` Prarit Bhargava
@ 2009-11-04  9:18   ` Thomas Gleixner
  2009-11-04 12:49     ` Yong Zhang
  1 sibling, 1 reply; 8+ messages in thread
From: Thomas Gleixner @ 2009-11-04  9:18 UTC (permalink / raw)
  To: Yong Zhang; +Cc: Prarit Bhargava, linux-kernel, ebiederm, akpm, Ingo Molnar

[-- Attachment #1: Type: TEXT/PLAIN, Size: 1174 bytes --]

On Tue, 3 Nov 2009, Yong Zhang wrote:

> > This happens because the &desc->lock is taken with spin_lock_irqsave and
> > just a spin_lock.  In the try_one_irq(), this lock really should be a
> > spin_lock_irqsave().
> >
> 
> Cc'ed Ingo and Thomas.
> 
> The reason is that try_one_irq() is called both from hardirq context and softirq
> context. And by default the timer handler poll_all_shared_irqs() is
> called with irq enabled.
> Then the two usage will cause inconsistent.
> 
> So I think the following patch is also workable to you.

Yes, that's sufficient.
 
> diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c
> index 114e704..11affbc 100644
> --- a/kernel/irq/spurious.c
> +++ b/kernel/irq/spurious.c
> @@ -111,6 +111,7 @@ static void poll_all_shared_irqs(void)
> 
>  	for_each_irq_desc(i, desc) {
>  		unsigned int status;
> +		unsigned long flags;
> 
>  		if (!i)
>  			 continue;
> @@ -121,7 +122,9 @@ static void poll_all_shared_irqs(void)
>  		if (!(status & IRQ_SPURIOUS_DISABLED))
>  			continue;
> 
> +		local_irq_save(flags);
>  		try_one_irq(i, desc);
> +		local_irq_restore(flags);

  You can even use local_irq_en/disable() here.

Thanks,

	tglx

^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH]: use spin_lock_irqsave in try_one_irq()
  2009-11-04  9:18   ` Thomas Gleixner
@ 2009-11-04 12:49     ` Yong Zhang
  2009-11-04 13:01       ` Yong Zhang
  0 siblings, 1 reply; 8+ messages in thread
From: Yong Zhang @ 2009-11-04 12:49 UTC (permalink / raw)
  To: Thomas Gleixner
  Cc: Prarit Bhargava, linux-kernel, ebiederm, akpm, Ingo Molnar

On Wed, Nov 4, 2009 at 5:18 PM, Thomas Gleixner <tglx@linutronix.de> wrote:
> On Tue, 3 Nov 2009, Yong Zhang wrote:
>
>> > This happens because the &desc->lock is taken with spin_lock_irqsave and
>> > just a spin_lock.  In the try_one_irq(), this lock really should be a
>> > spin_lock_irqsave().
>> >

>> So I think the following patch is also workable to you.
>
> Yes, that's sufficient.
>
>> diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c
>> index 114e704..11affbc 100644
>> --- a/kernel/irq/spurious.c
>> +++ b/kernel/irq/spurious.c
>> @@ -111,6 +111,7 @@ static void poll_all_shared_irqs(void)
>>
>>       for_each_irq_desc(i, desc) {
>>               unsigned int status;
>> +             unsigned long flags;
>>
>>               if (!i)
>>                        continue;
>> @@ -121,7 +122,9 @@ static void poll_all_shared_irqs(void)
>>               if (!(status & IRQ_SPURIOUS_DISABLED))
>>                       continue;
>>
>> +             local_irq_save(flags);
>>               try_one_irq(i, desc);
>> +             local_irq_restore(flags);
>
>  You can even use local_irq_en/disable() here.

Yup, I will resend the patch later.

Thanks,
Yong

>
> Thanks,
>
>        tglx

^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH]: use spin_lock_irqsave in try_one_irq()
  2009-11-04 12:49     ` Yong Zhang
@ 2009-11-04 13:01       ` Yong Zhang
  2009-11-04 13:17         ` Prarit Bhargava
  0 siblings, 1 reply; 8+ messages in thread
From: Yong Zhang @ 2009-11-04 13:01 UTC (permalink / raw)
  To: Thomas Gleixner
  Cc: Prarit Bhargava, linux-kernel, ebiederm, akpm, Ingo Molnar

>From 83ee4c7591aae764f1656bd68f6e95ae112e2e7a Mon Sep 17 00:00:00 2001
From: Yong Zhang <yong.zhang0@gmail.com>
Date: Wed, 4 Nov 2009 20:52:45 +0800
Subject: [PATCH] genirq: try_one_irq() should be called with irq disabled

Prarit report this:
Booting 2.6.32-rc5 on some IBM systems results in

Disabling IRQ #19

=================================
[ INFO: inconsistent lock state ]
2.6.32-rc5 #1
---------------------------------
inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage.
swapper/0 [HC0[0]:SC1[1]:HE1:SE0] takes:
 (&irq_desc_lock_class){?.-...}, at: [<ffffffff810c264e>] try_one_irq+0x32/0x138
{IN-HARDIRQ-W} state was registered at:
 [<ffffffff81095160>] __lock_acquire+0x2fc/0xd5d
 [<ffffffff81095cb4>] lock_acquire+0xf3/0x12d
 [<ffffffff814cdadd>] _spin_lock+0x40/0x89
 [<ffffffff810c3389>] handle_level_irq+0x30/0x105
 [<ffffffff81014e0e>] handle_irq+0x95/0xb7
 [<ffffffff810141bd>] do_IRQ+0x6a/0xe0
 [<ffffffff81012813>] ret_from_intr+0x0/0x16
irq event stamp: 195096
hardirqs last  enabled at (195096): [<ffffffff814cd7f7>]
_spin_unlock_irq+0x3a/0x5c
hardirqs last disabled at (195095): [<ffffffff814cdbdd>]
_spin_lock_irq+0x29/0x95
softirqs last  enabled at (195088): [<ffffffff81068c92>]
__do_softirq+0x1c1/0x1ef
softirqs last disabled at (195093): [<ffffffff8101304c>] call_softirq+0x1c/0x30

other info that might help us debug this:
1 lock held by swapper/0:
 #0:  (kernel/irq/spurious.c:21){+.-...}, at: [<ffffffff81070cf2>]
run_timer_softirq+0x1a9/0x315

stack backtrace:
Pid: 0, comm: swapper Not tainted 2.6.32-rc5 #1
Call Trace:
 <IRQ>  [<ffffffff81093e94>] valid_state+0x187/0x1ae
 [<ffffffff81096c7b>] ? check_usage_backwards+0x0/0xa3
 [<ffffffff81093fe4>] mark_lock+0x129/0x253
 [<ffffffff810951d4>] __lock_acquire+0x370/0xd5d
 [<ffffffff810c264e>] ? try_one_irq+0x32/0x138
 [<ffffffff8109329d>] ? save_trace+0x4e/0xcd
 [<ffffffff81095cb4>] lock_acquire+0xf3/0x12d
 [<ffffffff810c264e>] ? try_one_irq+0x32/0x138
 [<ffffffff81070cf2>] ? run_timer_softirq+0x1a9/0x315
 [<ffffffff810c264e>] ? try_one_irq+0x32/0x138
 [<ffffffff814cdadd>] _spin_lock+0x40/0x89
 [<ffffffff810c264e>] ? try_one_irq+0x32/0x138
 [<ffffffff810c264e>] try_one_irq+0x32/0x138
 [<ffffffff810c2795>] poll_all_shared_irqs+0x41/0x6d
 [<ffffffff810c27dd>] poll_spurious_irqs+0x1c/0x49
 [<ffffffff81070d82>] run_timer_softirq+0x239/0x315
 [<ffffffff81070cf2>] ? run_timer_softirq+0x1a9/0x315
 [<ffffffff810c27c1>] ? poll_spurious_irqs+0x0/0x49
 [<ffffffff81068bd3>] __do_softirq+0x102/0x1ef
 [<ffffffff8108eccf>] ? tick_dev_program_event+0x46/0xcc
 [<ffffffff8101304c>] call_softirq+0x1c/0x30
 [<ffffffff81014b65>] do_softirq+0x59/0xca
 [<ffffffff810686ad>] irq_exit+0x58/0xae
 [<ffffffff81029b84>] smp_apic_timer_interrupt+0x94/0xba
 [<ffffffff81012a33>] apic_timer_interrupt+0x13/0x20
 <EOI>  [<ffffffff8101a7b5>] ? mwait_idle+0x8c/0xb5
 [<ffffffff8101a7ac>] ? mwait_idle+0x83/0xb5
 [<ffffffff81010e55>] ? cpu_idle+0xbe/0x100
 [<ffffffff814c4270>] ? start_secondary+0x219/0x270

The reason is that try_one_irq() is called both from hardirq context
and softirq context. And by default the timer handler
poll_all_shared_irqs() is called with irq enabled.
Then the two usage will cause inconsistent.

Reported-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Yong Zhang <yong.zhang0@gmail.com>
---
 kernel/irq/spurious.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c
index 114e704..bd7273e 100644
--- a/kernel/irq/spurious.c
+++ b/kernel/irq/spurious.c
@@ -121,7 +121,9 @@ static void poll_all_shared_irqs(void)
 		if (!(status & IRQ_SPURIOUS_DISABLED))
 			continue;

+		local_irq_disable();
 		try_one_irq(i, desc);
+		local_irq_enable();
 	}
 }

-- 
1.6.3.3

^ permalink raw reply related	[flat|nested] 8+ messages in thread

* Re: [PATCH]: use spin_lock_irqsave in try_one_irq()
  2009-11-04 13:01       ` Yong Zhang
@ 2009-11-04 13:17         ` Prarit Bhargava
  0 siblings, 0 replies; 8+ messages in thread
From: Prarit Bhargava @ 2009-11-04 13:17 UTC (permalink / raw)
  To: Yong Zhang; +Cc: Thomas Gleixner, linux-kernel, ebiederm, akpm, Ingo Molnar



Yong Zhang wrote:
> From 83ee4c7591aae764f1656bd68f6e95ae112e2e7a Mon Sep 17 00:00:00 2001
> From: Yong Zhang <yong.zhang0@gmail.com>
> Date: Wed, 4 Nov 2009 20:52:45 +0800
> Subject: [PATCH] genirq: try_one_irq() should be called with irq disabled
>
> Prarit report this:
>   

<snip>

Testing verifies that this patch works.

P.

> Reported-by: Prarit Bhargava <prarit@redhat.com>
> Signed-off-by: Yong Zhang <yong.zhang0@gmail.com>
> ---
>  kernel/irq/spurious.c |    2 ++
>  1 files changed, 2 insertions(+), 0 deletions(-)
>
> diff --git a/kernel/irq/spurious.c b/kernel/irq/spurious.c
> index 114e704..bd7273e 100644
> --- a/kernel/irq/spurious.c
> +++ b/kernel/irq/spurious.c
> @@ -121,7 +121,9 @@ static void poll_all_shared_irqs(void)
>  		if (!(status & IRQ_SPURIOUS_DISABLED))
>  			continue;
>
> +		local_irq_disable();
>  		try_one_irq(i, desc);
> +		local_irq_enable();
>  	}
>  }
>
>   

^ permalink raw reply	[flat|nested] 8+ messages in thread

* [PATCH]: use spin_lock_irqsave in try_one_irq()
@ 2009-10-26 18:35 Prarit Bhargava
  0 siblings, 0 replies; 8+ messages in thread
From: Prarit Bhargava @ 2009-10-26 18:35 UTC (permalink / raw)
  To: linux-kernel, ebiederm; +Cc: Prarit Bhargava

Booting 2.6.32-rc5 on some IBM systems results in

Disabling IRQ #19

=================================
[ INFO: inconsistent lock state ]
2.6.32-rc5 #1
---------------------------------
inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage.
swapper/0 [HC0[0]:SC1[1]:HE1:SE0] takes:
 (&irq_desc_lock_class){?.-...}, at: [<ffffffff810c264e>] try_one_irq+0x32/0x138
{IN-HARDIRQ-W} state was registered at:
  [<ffffffff81095160>] __lock_acquire+0x2fc/0xd5d
  [<ffffffff81095cb4>] lock_acquire+0xf3/0x12d
  [<ffffffff814cdadd>] _spin_lock+0x40/0x89
  [<ffffffff810c3389>] handle_level_irq+0x30/0x105
  [<ffffffff81014e0e>] handle_irq+0x95/0xb7
  [<ffffffff810141bd>] do_IRQ+0x6a/0xe0
  [<ffffffff81012813>] ret_from_intr+0x0/0x16
irq event stamp: 195096
hardirqs last  enabled at (195096): [<ffffffff814cd7f7>] _spin_unlock_irq+0x3a/0x5c
hardirqs last disabled at (195095): [<ffffffff814cdbdd>] _spin_lock_irq+0x29/0x95
softirqs last  enabled at (195088): [<ffffffff81068c92>] __do_softirq+0x1c1/0x1ef
softirqs last disabled at (195093): [<ffffffff8101304c>] call_softirq+0x1c/0x30
 
other info that might help us debug this:
1 lock held by swapper/0:
 #0:  (kernel/irq/spurious.c:21){+.-...}, at: [<ffffffff81070cf2>] run_timer_softirq+0x1a9/0x315

stack backtrace:
Pid: 0, comm: swapper Not tainted 2.6.32-rc5 #1
Call Trace:
 <IRQ>  [<ffffffff81093e94>] valid_state+0x187/0x1ae
 [<ffffffff81096c7b>] ? check_usage_backwards+0x0/0xa3
 [<ffffffff81093fe4>] mark_lock+0x129/0x253
 [<ffffffff810951d4>] __lock_acquire+0x370/0xd5d
 [<ffffffff810c264e>] ? try_one_irq+0x32/0x138
 [<ffffffff8109329d>] ? save_trace+0x4e/0xcd
 [<ffffffff81095cb4>] lock_acquire+0xf3/0x12d
 [<ffffffff810c264e>] ? try_one_irq+0x32/0x138
 [<ffffffff81070cf2>] ? run_timer_softirq+0x1a9/0x315
 [<ffffffff810c264e>] ? try_one_irq+0x32/0x138
 [<ffffffff814cdadd>] _spin_lock+0x40/0x89
 [<ffffffff810c264e>] ? try_one_irq+0x32/0x138
 [<ffffffff810c264e>] try_one_irq+0x32/0x138
 [<ffffffff810c2795>] poll_all_shared_irqs+0x41/0x6d
 [<ffffffff810c27dd>] poll_spurious_irqs+0x1c/0x49
 [<ffffffff81070d82>] run_timer_softirq+0x239/0x315
 [<ffffffff81070cf2>] ? run_timer_softirq+0x1a9/0x315
 [<ffffffff810c27c1>] ? poll_spurious_irqs+0x0/0x49
 [<ffffffff81068bd3>] __do_softirq+0x102/0x1ef
 [<ffffffff8108eccf>] ? tick_dev_program_event+0x46/0xcc
 [<ffffffff8101304c>] call_softirq+0x1c/0x30
 [<ffffffff81014b65>] do_softirq+0x59/0xca
 [<ffffffff810686ad>] irq_exit+0x58/0xae
 [<ffffffff81029b84>] smp_apic_timer_interrupt+0x94/0xba
 [<ffffffff81012a33>] apic_timer_interrupt+0x13/0x20
 <EOI>  [<ffffffff8101a7b5>] ? mwait_idle+0x8c/0xb5
 [<ffffffff8101a7ac>] ? mwait_idle+0x83/0xb5
 [<ffffffff81010e55>] ? cpu_idle+0xbe/0x100
 [<ffffffff814c4270>] ? start_secondary+0x219/0x270

This happens because the &desc->lock is taken with spin_lock_irqsave and
just a spin_lock.  In the try_one_irq(), this lock really should be a
spin_lock_irqsave().

I have not yet narrowed down the reason for the spurious interrupt (although
I suspect it maybe to do with the radeon driver).

Successfully tested by me.

Signed-off-by: Prarit Bhargava <prarit@redhat.com>

--- linux-2.6.31.x86_64.orig/kernel/irq/spurious.c	2009-09-09 18:13:59.000000000 -0400
+++ linux-2.6.31.x86_64/kernel/irq/spurious.c	2009-10-26 10:55:56.709845786 -0400
@@ -27,8 +27,9 @@ static int try_one_irq(int irq, struct i
 {
 	struct irqaction *action;
 	int ok = 0, work = 0;
+	unsigned long flags;
 
-	spin_lock(&desc->lock);
+	spin_lock_irqsave(&desc->lock, flags);
 	/* Already running on another processor */
 	if (desc->status & IRQ_INPROGRESS) {
 		/*
@@ -37,13 +38,13 @@ static int try_one_irq(int irq, struct i
 		 */
 		if (desc->action && (desc->action->flags & IRQF_SHARED))
 			desc->status |= IRQ_PENDING;
-		spin_unlock(&desc->lock);
+		spin_unlock_irqrestore(&desc->lock, flags);
 		return ok;
 	}
 	/* Honour the normal IRQ locking */
 	desc->status |= IRQ_INPROGRESS;
 	action = desc->action;
-	spin_unlock(&desc->lock);
+	spin_unlock_irqrestore(&desc->lock, flags);
 
 	while (action) {
 		/* Only shared IRQ handlers are safe to call */
@@ -56,7 +57,7 @@ static int try_one_irq(int irq, struct i
 	}
 	local_irq_disable();
 	/* Now clean up the flags */
-	spin_lock(&desc->lock);
+	spin_lock_irqsave(&desc->lock, flags);
 	action = desc->action;
 
 	/*
@@ -68,9 +69,9 @@ static int try_one_irq(int irq, struct i
 		 * Perform real IRQ processing for the IRQ we deferred
 		 */
 		work = 1;
-		spin_unlock(&desc->lock);
+		spin_unlock_irqrestore(&desc->lock, flags);
 		handle_IRQ_event(irq, action);
-		spin_lock(&desc->lock);
+		spin_lock_irqsave(&desc->lock, flags);
 		desc->status &= ~IRQ_PENDING;
 	}
 	desc->status &= ~IRQ_INPROGRESS;
@@ -80,7 +81,7 @@ static int try_one_irq(int irq, struct i
 	 */
 	if (work && desc->chip && desc->chip->end)
 		desc->chip->end(irq);
-	spin_unlock(&desc->lock);
+	spin_unlock_irqrestore(&desc->lock, flags);
 
 	return ok;
 }

^ permalink raw reply	[flat|nested] 8+ messages in thread

end of thread, other threads:[~2009-11-04 13:22 UTC | newest]

Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2009-11-03 13:45 [PATCH]: use spin_lock_irqsave in try_one_irq() Prarit Bhargava
2009-11-03 14:58 ` Yong Zhang
2009-11-03 15:03   ` Prarit Bhargava
2009-11-04  9:18   ` Thomas Gleixner
2009-11-04 12:49     ` Yong Zhang
2009-11-04 13:01       ` Yong Zhang
2009-11-04 13:17         ` Prarit Bhargava
  -- strict thread matches above, loose matches on Subject: below --
2009-10-26 18:35 Prarit Bhargava

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.