[PATCH] Documentation / cpu hotplug: remove outdated description for MADT entries

[PATCH] Documentation / cpu hotplug: remove outdated description for MADT entries

[Hanjun Guo]

More than 256 entries in ACPI MADT is supported from ACPI 3.0 Specification,
So the outdated description for MADT entries should be removed.

Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
---
 Documentation/cpu-hotplug.txt |    3 ---
 1 file changed, 3 deletions(-)

diff --git a/Documentation/cpu-hotplug.txt b/Documentation/cpu-hotplug.txt
index 9f40135..2e36e40 100644
--- a/Documentation/cpu-hotplug.txt
+++ b/Documentation/cpu-hotplug.txt
@@ -370,9 +370,6 @@ A: There is no clear spec defined way from ACPI that can give us that
    CPUs in MADT as hotpluggable CPUS.  In the case there are no disabled CPUS
    we assume 1/2 the number of CPUs currently present can be hotplugged.
 
-   Caveat: Today's ACPI MADT can only provide 256 entries since the apicid field
-   in MADT is only 8 bits.
-
 User Space Notification
 
 Hotplug support for devices is common in Linux today. Its being used today to
-- 
1.7.9.5

Re: [PATCH] Documentation / cpu hotplug: remove outdated description for MADT entries

[Rafael J. Wysocki]

On Thursday, June 20, 2013 04:54:42 PM Hanjun Guo wrote:
> More than 256 entries in ACPI MADT is supported from ACPI 3.0 Specification,
> So the outdated description for MADT entries should be removed.

Well, it kind of is still valid for systems pre-dating ACPI 3.0, isn't it?

So perhaps instead of simply removing that information it would be better to
rephrase it?

Thanks,
Rafael


> Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
> ---
>  Documentation/cpu-hotplug.txt |    3 ---
>  1 file changed, 3 deletions(-)
> 
> diff --git a/Documentation/cpu-hotplug.txt b/Documentation/cpu-hotplug.txt
> index 9f40135..2e36e40 100644
> --- a/Documentation/cpu-hotplug.txt
> +++ b/Documentation/cpu-hotplug.txt
> @@ -370,9 +370,6 @@ A: There is no clear spec defined way from ACPI that can give us that
>     CPUs in MADT as hotpluggable CPUS.  In the case there are no disabled CPUS
>     we assume 1/2 the number of CPUs currently present can be hotplugged.
>  
> -   Caveat: Today's ACPI MADT can only provide 256 entries since the apicid field
> -   in MADT is only 8 bits.
> -
>  User Space Notification
>  
>  Hotplug support for devices is common in Linux today. Its being used today to
> 
-- 
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.

Re: [PATCH] Documentation / cpu hotplug: remove outdated description for MADT entries

[Hanjun Guo]

On 2013-6-21 3:52, Rafael J. Wysocki wrote:
> On Thursday, June 20, 2013 04:54:42 PM Hanjun Guo wrote:
>> More than 256 entries in ACPI MADT is supported from ACPI 3.0 Specification,
>> So the outdated description for MADT entries should be removed.
> 
> Well, it kind of is still valid for systems pre-dating ACPI 3.0, isn't it?

Yes, it is.

> 
> So perhaps instead of simply removing that information it would be better to
> rephrase it?

Good idea, I will update my patch and send out soon.

Thanks
Hanjun

> 
> Thanks,
> Rafael
> 
> 
>> Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
>> ---
>>  Documentation/cpu-hotplug.txt |    3 ---
>>  1 file changed, 3 deletions(-)
>>
>> diff --git a/Documentation/cpu-hotplug.txt b/Documentation/cpu-hotplug.txt
>> index 9f40135..2e36e40 100644
>> --- a/Documentation/cpu-hotplug.txt
>> +++ b/Documentation/cpu-hotplug.txt
>> @@ -370,9 +370,6 @@ A: There is no clear spec defined way from ACPI that can give us that
>>     CPUs in MADT as hotpluggable CPUS.  In the case there are no disabled CPUS
>>     we assume 1/2 the number of CPUs currently present can be hotplugged.
>>  
>> -   Caveat: Today's ACPI MADT can only provide 256 entries since the apicid field
>> -   in MADT is only 8 bits.
>> -
>>  User Space Notification
>>  
>>  Hotplug support for devices is common in Linux today. Its being used today to
>>

Re: [PATCH] Documentation / cpu hotplug: remove outdated description for MADT entries

[Rob Landley]

On 06/20/2013 03:54:42 AM, Hanjun Guo wrote:
> More than 256 entries in ACPI MADT is supported from ACPI 3.0  
> Specification,
> So the outdated description for MADT entries should be removed.
> 
> Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
> ---
>  Documentation/cpu-hotplug.txt |    3 ---
>  1 file changed, 3 deletions(-)

Acked-by: Rob Landley <rob@landley.net>

> diff --git a/Documentation/cpu-hotplug.txt  
> b/Documentation/cpu-hotplug.txt
> index 9f40135..2e36e40 100644
> --- a/Documentation/cpu-hotplug.txt
> +++ b/Documentation/cpu-hotplug.txt
> @@ -370,9 +370,6 @@ A: There is no clear spec defined way from ACPI  
> that can give us that
>     CPUs in MADT as hotpluggable CPUS.  In the case there are no  
> disabled CPUS
>     we assume 1/2 the number of CPUs currently present can be  
> hotplugged.
> 
> -   Caveat: Today's ACPI MADT can only provide 256 entries since the  
> apicid field
> -   in MADT is only 8 bits.
> -
>  User Space Notification
> 
>  Hotplug support for devices is common in Linux today. Its being used  
> today to
> --
> 1.7.9.5
> 
> 

Re: [PATCH] Documentation / cpu hotplug: remove outdated description for MADT entries

[Jiri Kosina]

On Thu, 20 Jun 2013, Rob Landley wrote:

> On 06/20/2013 03:54:42 AM, Hanjun Guo wrote:
> > More than 256 entries in ACPI MADT is supported from ACPI 3.0 Specification,
> > So the outdated description for MADT entries should be removed.
> > 
> > Signed-off-by: Hanjun Guo <hanjun.guo@linaro.org>
> > ---
> > Documentation/cpu-hotplug.txt |    3 ---
> > 1 file changed, 3 deletions(-)
> 
> Acked-by: Rob Landley <rob@landley.net>

I am not taking this one, as I think the information should be kept there 
to reflect the state on systems that are not 3.0-compliant.

-- 
Jiri Kosina
SUSE Labs