Re: [PATCH 4/8] SGI x86_64 UV: Limit the number of ACPI messages

[Mike Travis <travis@sgi.com>]

Thomas Renninger wrote:
> On Saturday 24 October 2009 05:29:47 am Bjorn Helgaas wrote:
>> On Fri, 2009-10-23 at 18:37 -0500, Mike Travis wrote:
>>> plain text document attachment (limit_acpi)
>>> Limit number of ACPI messages of the form:
>>>
>>> [    0.000000] ACPI: LSAPIC (acpi_id[0x00] lsapic_id[0x00]
>>> lsapic_eid[0x00] enabled)
>>>
>>> [   99.638655] processor ACPI0007:00: registered as cooling_device0
>>>
>>> Cc: Zhang Rui <rui.zhang@intel.com>
>>> Cc: Len Brown <lenb@kernel.org>
>>> Cc: Thomas Renninger <trenn@suse.de>
>>> Cc: Bjorn Helgaas <bjorn.helgaas@hp.com>
>>> Cc: Alexey Dobriyan <adobriyan@gmail.com>
>>> Cc: Myron Stowe <myron.stowe@hp.com>
>>> Cc: Feng Tang <feng.tang@intel.com>
>>> Cc: Suresh Siddha <suresh.b.siddha@intel.com>
>>> Cc: Yinghai Lu <yhlu.kernel@gmail.com>
>>> Cc: linux-acpi@vger.kernel.org
>>> Cc: linux-kernel@vger.kernel.org
>>> Signed-off-by: Mike Travis <travis@sgi.com>
>>> ---
>>>  drivers/acpi/fan.c            |    7 ++++++-
>>>  drivers/acpi/processor_core.c |    8 ++++++--
>>>  drivers/acpi/tables.c         |   15 ++++++++++-----
>>>  3 files changed, 22 insertions(+), 8 deletions(-)
>>>
>>> --- linux.orig/drivers/acpi/fan.c
>>> +++ linux/drivers/acpi/fan.c
>>> @@ -243,6 +243,7 @@
>>>  	int result = 0;
>>>  	int state = 0;
>>>  	struct thermal_cooling_device *cdev;
>>> +	static int msgcnt;
>>>
>>>  	if (!device)
>>>  		return -EINVAL;
>>> @@ -267,7 +268,11 @@
>>>  		goto end;
>>>  	}
>>>
>>> -	dev_info(&device->dev, "registered as cooling_device%d\n", cdev->id);
>>> +	if (msgcnt < 4 || !limit_console_output(false)) {
>>> +		dev_info(&device->dev,
>>> +			"registered as cooling_device%d\n", cdev->id);
>>> +		msgcnt++;
>>> +	}
>> I'm personally not in favor of printing some, but not all, of these
>> messages.  That leads to questions when analyzing a dmesg log, such as
>> "Hmm, I see I have 64 CPUs, but only 0-3 are registered as cooling
>> devices.  Does that mean something is wrong?"
>>
>> But I would be glad to see this particular message removed completely.
>>
>>>  	device->driver_data = cdev;
>>>  	result = sysfs_create_link(&device->dev.kobj,
>>> --- linux.orig/drivers/acpi/processor_core.c
>>> +++ linux/drivers/acpi/processor_core.c
>>> @@ -775,6 +775,7 @@
>>>  	struct acpi_processor *pr = NULL;
>>>  	int result = 0;
>>>  	struct sys_device *sysdev;
>>> +	static int msgcnt;
>>>
>>>  	pr = kzalloc(sizeof(struct acpi_processor), GFP_KERNEL);
>>>  	if (!pr)
>>> @@ -845,8 +846,11 @@
>>>  		goto err_power_exit;
>>>  	}
>>>
>>> -	dev_info(&device->dev, "registered as cooling_device%d\n",
>>> -		 pr->cdev->id);
>>> +	if (msgcnt < 4 || !limit_console_output(false)) {
>>> +		dev_info(&device->dev, "registered as cooling_device%d\n",
>>> +			 pr->cdev->id);
>>> +		msgcnt++;
>>> +	}
> If Zhang Rui does not complain you can change these:
> ..registered as cooling_device..
> into dev_dbg() without any condition.
> This isn't critical.
> 
> Or why not use the more fine grained
> ACPI debug facility and change it into:
> ACPI_DEBUG_PRINT((ACPI_DB_INFO "..."));
> (compare with Documentation/acpi/debug.txt and other
> occurences in the same file)
> You have to pass:
> acpi_dbg_layer=0x20000000
> to see it then.

Ok.
>>>  	result = sysfs_create_link(&device->dev.kobj,
>>>  				   &pr->cdev->device.kobj,
>>> --- linux.orig/drivers/acpi/tables.c
>>> +++ linux/drivers/acpi/tables.c
>>> @@ -170,11 +170,16 @@
>>>  	case ACPI_MADT_TYPE_LOCAL_SAPIC:
>>>  		{
>>>  			struct acpi_madt_local_sapic *p =
>>> -			    (struct acpi_madt_local_sapic *)header;
>>> -			printk(KERN_INFO PREFIX
>>> -			       "LSAPIC (acpi_id[0x%02x] lsapic_id[0x%02x] lsapic_eid[0x%02x]
>>> %s)\n", -			       p->processor_id, p->id, p->eid,
>>> -			       (p->lapic_flags & ACPI_MADT_ENABLED) ? "enabled" :
>>> "disabled"); +				(struct acpi_madt_local_sapic *)header;
>>> +
>>> +			if (p->eid < 8 || !limit_console_output(false))
> I can't find limit_console_output(), I expect it got introduced by another one 
> of your patch series, not send to the acpi list?
> Still shouldn't this be:
> limit_console_output(true)
> instead of:
> !limit_console_output(false)
> 
>        Thomas

Sorry, I used a semi-auto method of calling get_maintainer which filled each patch
with specific Cc's.  I did send the first one to everyone in hopes that that would
help find the others.

See http://marc.info/?l=linux-kernel&m=125634109621411&w=4   (the argument specifies
whether to reduce the console loglevel.  It's currently only used to suppress the
cpu bootup messages.)

Thanks,
Mike

> 
>>> +				printk(KERN_INFO PREFIX
>>> +					"LSAPIC (acpi_id[0x%02x] "
>>> +						"lsapic_id[0x%02x] "
>>> +						"lsapic_eid[0x%02x] %s)\n",
>>> +					p->processor_id, p->id, p->eid,
>>> +					(p->lapic_flags & ACPI_MADT_ENABLED) ?
>>> +						"enabled" : "disabled");
>> I know we print way too much stuff for every processor, but again, I'd
>> rather see all CPUs or none.  I think there's a little more value in
>> this one than the cooling device one (probably because I do a lot of
>> platform bringup), but it could certainly be made KERN_DEBUG and/or
>> combined with another processor discovery line.