linux-toradex.git/kernel/irq/proc.c, branch v2.6.27.5

genirq: switch /proc/irq/*/smp_affinity et al to seqfiles

2008-08-12T23:07:30+00:00

Switch /proc/irq/*/smp_affinity , /proc/irq/default_smp_affinity to
seq_files.

cat(1) reads with 1024 chunks by default, with high enough NR_CPUS, there
will be -EINVAL.

As side effect, there are now two less users of the ->read_proc interface.

Signed-off-by: Alexey Dobriyan 
Cc: Paul Jackson 
Cc: Mike Travis 
Cc: Al Viro 
Cc: Ingo Molnar 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

genirq: Expose default irq affinity mask (take 3)

2008-06-05T13:18:30+00:00

Current IRQ affinity interface does not provide a way to set affinity
for the IRQs that will be allocated/activated in the future.
This patch creates /proc/irq/default_smp_affinity that lets users set
default affinity mask for the newly allocated IRQs. Changing the default
does not affect affinity masks for the currently active IRQs, they
have to be changed explicitly.

Updated based on Paul J's comments and added some more documentation.

Signed-off-by: Max Krasnyansky 
Cc: pj@sgi.com
Cc: a.p.zijlstra@chello.nl
Cc: tglx@linutronix.de
Cc: rdunlap@xenotime.net
Cc: mingo@elte.hu
Signed-off-by: Thomas Gleixner

x86: add /proc/irq/*/spurious to dump the spurious irq debugging state

2008-01-30T12:32:48+00:00

This is useful to debug problems with interrupt handlers that return
sometimes IRQ_NONE.

Signed-off-by: Andi Kleen 
Signed-off-by: Ingo Molnar 
Signed-off-by: Thomas Gleixner

x86_64: Report the pending irq if available in smp_affinity

2007-07-22T01:37:07+00:00

Otherwise smp_affinity would only update after the next interrupt
on x86 systems.

Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Signed-off-by: Andi Kleen 
Signed-off-by: Linus Torvalds

[IA64] SN: validate smp_affinity mask on intr redirect

2007-05-11T16:35:38+00:00

On SN, only allow one bit to be set in the smp_affinty mask when
redirecting an interrupt.  Currently setting multiple bits is allowed, but
only the first bit is used in determining the CPU to redirect to.  This has
caused confusion among some customers.

[akpm@linux-foundation.org: fixes]
Signed-off-by: John Keller 
Signed-off-by: Andrew Morton 
Signed-off-by: Tony Luck

kernel/irq/proc.c: unprotected iteration over the IRQ action list in name_unique()

2007-05-08T18:15:05+00:00

setup_irq() releases a desc->lock before calling register_handler_proc(), so
the iteration over the IRQ action list is not protected.

(akpm: the check itself is still racy, but at least it probably won't oops
now).

Cc: Ingo Molnar 
Cc: Thomas Gleixner 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] Add a function to handle interrupt affinity setting

2007-02-16T16:13:56+00:00

Provide funtions to:
 - check, whether an interrupt can set the affinity
 - pin the interrupt to a given cpu

Necessary for the ability to setup clocksources more flexible (e.g.  use the
different HPET channels per CPU)

[akpm@osdl.org: alpha build fix]
Signed-off-by: Thomas Gleixner 
Signed-off-by: Ingo Molnar 
Cc: john stultz 
Cc: Roman Zippel 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] Add irq flag to disable balancing for an interrupt

2007-02-16T16:13:56+00:00

Add a flag so we can prevent the irq balancing of an interrupt.  Move the
bits, so we have room for more :)

Necessary for the ability to setup clocksources more flexible (e.g.  use the
different HPET channels per CPU)

Signed-off-by: Thomas Gleixner 
Signed-off-by: Ingo Molnar 
Cc: john stultz 
Cc: Roman Zippel 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] proc: remove useless (and buggy) ->nlink settings

2007-02-11T18:51:32+00:00

Bug: pnx8550 code creates directory but resets ->nlink to 1.

create_proc_entry() et al will correctly set ->nlink for you.

Signed-off-by: Alexey Dobriyan 
Cc: Ralf Baechle 
Cc: Benjamin Herrenschmidt 
Cc: Paul Mackerras 
Cc: Jeff Dike 
Cc: Corey Minyard 
Cc: Alan Cox 
Cc: Kyle McMartin 
Cc: Martin Schwidefsky 
Cc: Greg KH 
Cc: Ingo Molnar 
Cc: Thomas Gleixner 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] CPEI gets warning at kernel/irq/migration.c:27/move_masked_irq()

2006-12-08T16:28:37+00:00

While running my MCA test (hardware error injection) on 2.6.19,
I got some warning like following:

> BUG: warning at kernel/irq/migration.c:27/move_masked_irq()
>
> Call Trace:
>  [] show_stack+0x40/0xa0
>                                 sp=e00000006b2578d0 bsp=e00000006b2510b0
>  [] dump_stack+0x30/0x60
>                                 sp=e00000006b257aa0 bsp=e00000006b251098
>  [] move_masked_irq+0xb0/0x240
>                                 sp=e00000006b257aa0 bsp=e00000006b251070
>  [] move_native_irq+0xe0/0x180
>                                 sp=e00000006b257aa0 bsp=e00000006b251040
>  [] iosapic_end_level_irq+0x30/0xe0
>                                 sp=e00000006b257aa0 bsp=e00000006b251020
>  [] __do_IRQ+0x170/0x400
>                                 sp=e00000006b257aa0 bsp=e00000006b250fd8
>  [] ia64_handle_irq+0x1b0/0x260
>                                 sp=e00000006b257aa0 bsp=e00000006b250fa8
>  [] ia64_leave_kernel+0x0/0x280
>                                 sp=e00000006b257aa0 bsp=e00000006b250fa8
>  [] _spin_unlock_irqrestore+0x30/0x60
>                                 sp=e00000006b257c70 bsp=e00000006b250f90

It comes from:

[kernel/irq/migration.c]
  26         if (CHECK_IRQ_PER_CPU(desc->status)) {
  27                 WARN_ON(1);
  28                 return;
  29         }

By putting some printk in kernel, I found that irqbalance is trying to
move CPEI which is handled as PER_CPU irq. That's why.

CPEI(Corrected Platform Error Interrupt) is ia64 specific irq, is
allowed to pin to particular processor which selected by the platform, and
even it is PER_CPU but it has set_affinity handler (=iosapic_set_affinity)
as same as other IO-SAPIC-level interrupts. (I don't know why, but
I guess that there would be typical situation where the handler for
migration is needed, such as hotplug - the processor going to be
offline/hot-removed.)

To shut up this warning, there are 2 way at least:
 a) fix CPEI stuff
 b) prohibit setting affinity to PER_CPU irq

I'm not sure what stuff of CPEI need to be fixed, but I think that
returning error to attempting move PER_CPU irq is useful for all
applications since it will never work.

Following small patch takes b) style.
It works, the warning disappeared and irqbalance still runs well.

Signed-off-by: Hidetoshi Seto 
Cc: Arjan van de Ven 
Acked-by: Ingo Molnar 
Acked-by: Thomas Gleixner 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds