[PATCH 0/3] n450: add 2.6.37 kernel recipe and SMP support

[PATCH 0/3] n450: add 2.6.37 kernel recipe and SMP support

[Darren Hart]

The atom-pc BSP which the n450 is based on was originally intended for single
CPU. The n450 is a single-core hyperthreaded CPU, so CONFIG_SMP and
CONFIG_SCHED_SMT are required to access the second hardware thread. These
patches add the newly created cfg/smp.scc config fragment to the recipe.

The current n450 BSP uses linux-yocto-stable (2.6.34), which was an oversight.
These patches add support for the linux-yocto (2.6.37) recipe and separately
enable that as the default. I have tested the linux-yocto kernel and confirmed
it boots, has functional networking, and can suspend and resume.

After some discussion with Tom, it seems that there is adequate testing planned
for the point release to allow for moving to the linux-yocto recipe. Note that
fixing bug 1010 makes significant changes to whichever kernel we choose
to use. Before I commit to meta-intel however, I would like the input of the QA
team.

How much testing was planned for the n450 originally? How much additional
testing would be required if we make the new kernel the default?

Thanks,

Darren Hart

[PATCH 1/3] n450: enable SMP and SCHED_SMT

[Darren Hart]

Fixes [YOCTO 1010]

The Atom N450 CPU is single core with hyperthreading. Update the kernel recipe
to build with CONFIG_SMP and CONFIG_SCHED_SMT.

Signed-off-by: Darren Hart <dvhart@linux.intel.com>
---
 .../linux/linux-yocto-stable_git.bbappend          |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/meta-n450/recipes-kernel/linux/linux-yocto-stable_git.bbappend b/meta-n450/recipes-kernel/linux/linux-yocto-stable_git.bbappend
index e7c2df8..e69c644 100644
--- a/meta-n450/recipes-kernel/linux/linux-yocto-stable_git.bbappend
+++ b/meta-n450/recipes-kernel/linux/linux-yocto-stable_git.bbappend
@@ -2,6 +2,9 @@ FILESEXTRAPATHS := "${THISDIR}/${PN}"
 KMACHINE_n450 = "atom-pc"
 COMPATIBLE_MACHINE_n450 = "n450"
 
+# The n450 is a single core hypterthreaded CPU
+KERNEL_FEATURES_append_n450 += " cfg/smp.scc"
+
 # We use the atom-pc machine SRCREV and the default meta SRCREV
 #SRCREV_machine_pn-linux-yocto-stable_n450 = ""
 #SRCREV_meta_pn-linux-yocto-stable_n450 ?= ""
-- 
1.7.1

[PATCH 2/3] n450: add linux_yocto (2.6.37) bbappend

[Darren Hart]

Signed-off-by: Darren Hart <dvhart@linux.intel.com>
---
 .../recipes-kernel/linux/linux-yocto_git.bbappend  |   10 ++++++++++
 1 files changed, 10 insertions(+), 0 deletions(-)
 create mode 100644 meta-n450/recipes-kernel/linux/linux-yocto_git.bbappend

diff --git a/meta-n450/recipes-kernel/linux/linux-yocto_git.bbappend b/meta-n450/recipes-kernel/linux/linux-yocto_git.bbappend
new file mode 100644
index 0000000..79706d5
--- /dev/null
+++ b/meta-n450/recipes-kernel/linux/linux-yocto_git.bbappend
@@ -0,0 +1,10 @@
+FILESEXTRAPATHS := "${THISDIR}/${PN}"
+KMACHINE_n450 = "yocto/standard/common-pc/atom-pc"
+COMPATIBLE_MACHINE_n450 = "n450"
+
+# The n450 is a single core hypterthreaded CPU
+KERNEL_FEATURES_append_n450 += " cfg/smp.scc"
+
+# We use the atom-pc machine SRCREV and the default meta SRCREV
+#SRCREV_machine_pn-linux-yocto-stable_n450 = ""
+#SRCREV_meta_pn-linux-yocto-stable_n450 ?= ""
-- 
1.7.1

[PATCH 3/3] n450: use linux-yocto (2.6.37) by default

[Darren Hart]

Signed-off-by: Darren Hart <dvhart@linux.intel.com>
---
 meta-n450/conf/machine/n450.conf |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/meta-n450/conf/machine/n450.conf b/meta-n450/conf/machine/n450.conf
index c06cb6c..f9cf4f2 100644
--- a/meta-n450/conf/machine/n450.conf
+++ b/meta-n450/conf/machine/n450.conf
@@ -9,7 +9,7 @@ SYSLINUX_OPTS = "serial 0 115200"
 SERIAL_CONSOLE = "115200 ttyS0" 
 APPEND += "console=ttyS0,115200 console=tty0" 
 
-PREFERRED_PROVIDER_virtual/kernel ?= "linux-yocto-stable"
+PREFERRED_PROVIDER_virtual/kernel ?= "linux-yocto"
 
 # Ensure the bsp packages are installed
 MACHINE_EXTRA_RRECOMMENDS += " n450-audio "
-- 
1.7.1

Re: [PATCH 0/3] n450: add 2.6.37 kernel recipe and SMP support

[Bruce Ashfield]

On 11-04-27 03:51 PM, Darren Hart wrote:
> The atom-pc BSP which the n450 is based on was originally intended for single
> CPU. The n450 is a single-core hyperthreaded CPU, so CONFIG_SMP and
> CONFIG_SCHED_SMT are required to access the second hardware thread. These
> patches add the newly created cfg/smp.scc config fragment to the recipe.
>
> The current n450 BSP uses linux-yocto-stable (2.6.34), which was an oversight.
> These patches add support for the linux-yocto (2.6.37) recipe and separately
> enable that as the default. I have tested the linux-yocto kernel and confirmed
> it boots, has functional networking, and can suspend and resume.
>
> After some discussion with Tom, it seems that there is adequate testing planned
> for the point release to allow for moving to the linux-yocto recipe. Note that
> fixing bug 1010 makes significant changes to whichever kernel we choose

Was this supposed to read "does not make significant changes" ? Looks
pretty minor to me (outside of jumping kernels :).

> to use. Before I commit to meta-intel however, I would like the input of the QA
> team.
>
> How much testing was planned for the n450 originally? How much additional
> testing would be required if we make the new kernel the default?

For what its worth our other x86 testing should have largely covered
this. If we can't count on the transitive value of our testing using
the common fragments/drivers/arch, then we don't have much to count on.

I see little risk in this myself, and would support the default changing
to linux-yocto in 1.0.1.

Acked-by: Bruce Ashfield <bruce.ashfield@windriver.com>

>
> Thanks,
>
> Darren Hart
>

Re: [PATCH 0/3] n450: add 2.6.37 kernel recipe and SMP support

[Darren Hart]

On 04/27/2011 12:59 PM, Bruce Ashfield wrote:
> On 11-04-27 03:51 PM, Darren Hart wrote:
>> The atom-pc BSP which the n450 is based on was originally intended for single
>> CPU. The n450 is a single-core hyperthreaded CPU, so CONFIG_SMP and
>> CONFIG_SCHED_SMT are required to access the second hardware thread. These
>> patches add the newly created cfg/smp.scc config fragment to the recipe.
>>
>> The current n450 BSP uses linux-yocto-stable (2.6.34), which was an oversight.
>> These patches add support for the linux-yocto (2.6.37) recipe and separately
>> enable that as the default. I have tested the linux-yocto kernel and confirmed
>> it boots, has functional networking, and can suspend and resume.
>>
>> After some discussion with Tom, it seems that there is adequate testing planned
>> for the point release to allow for moving to the linux-yocto recipe. Note that
>> fixing bug 1010 makes significant changes to whichever kernel we choose
> 
> Was this supposed to read "does not make significant changes" ? Looks
> pretty minor to me (outside of jumping kernels :).

Actually no. There was some concern about jumping kernels and I just
want to point out that enabling SMP changes the way a number of things
work within the kernel, so some retesting might be necessary anyway. If
so, then the jump to 2.6.37 isn't as big of a deal.

> 
>> to use. Before I commit to meta-intel however, I would like the input of the QA
>> team.
>>
>> How much testing was planned for the n450 originally? How much additional
>> testing would be required if we make the new kernel the default?
> 
> For what its worth our other x86 testing should have largely covered
> this. If we can't count on the transitive value of our testing using
> the common fragments/drivers/arch, then we don't have much to count on.
> 
> I see little risk in this myself, and would support the default changing
> to linux-yocto in 1.0.1.

Excellent point Bruce!

> 
> Acked-by: Bruce Ashfield <bruce.ashfield@windriver.com>
> 
>>
>> Thanks,
>>
>> Darren Hart
>>
> 

-- 
Darren Hart
Intel Open Source Technology Center
Yocto Project - Linux Kernel

Re: [PATCH 0/3] n450: add 2.6.37 kernel recipe and SMP support

[Bruce Ashfield]

On Wed, Apr 27, 2011 at 6:19 PM, Darren Hart <dvhart@linux.intel.com> wrote:
>
>
> On 04/27/2011 12:59 PM, Bruce Ashfield wrote:
>> On 11-04-27 03:51 PM, Darren Hart wrote:
>>> The atom-pc BSP which the n450 is based on was originally intended for single
>>> CPU. The n450 is a single-core hyperthreaded CPU, so CONFIG_SMP and
>>> CONFIG_SCHED_SMT are required to access the second hardware thread. These
>>> patches add the newly created cfg/smp.scc config fragment to the recipe.
>>>
>>> The current n450 BSP uses linux-yocto-stable (2.6.34), which was an oversight.
>>> These patches add support for the linux-yocto (2.6.37) recipe and separately
>>> enable that as the default. I have tested the linux-yocto kernel and confirmed
>>> it boots, has functional networking, and can suspend and resume.
>>>
>>> After some discussion with Tom, it seems that there is adequate testing planned
>>> for the point release to allow for moving to the linux-yocto recipe. Note that
>>> fixing bug 1010 makes significant changes to whichever kernel we choose
>>
>> Was this supposed to read "does not make significant changes" ? Looks
>> pretty minor to me (outside of jumping kernels :).
>
> Actually no. There was some concern about jumping kernels and I just
> want to point out that enabling SMP changes the way a number of things
> work within the kernel, so some retesting might be necessary anyway. If
> so, then the jump to 2.6.37 isn't as big of a deal.

Aha. Understood, I was thinking in terms of patches/config, or some
other pending changes. But yes, switching to SMP is a under the
covers big change .. but nothing I wouldn't lump into the 'tested by
other BSPs' category I mentioned before.

Cheers,

Bruce

>
>>
>>> to use. Before I commit to meta-intel however, I would like the input of the QA
>>> team.
>>>
>>> How much testing was planned for the n450 originally? How much additional
>>> testing would be required if we make the new kernel the default?
>>
>> For what its worth our other x86 testing should have largely covered
>> this. If we can't count on the transitive value of our testing using
>> the common fragments/drivers/arch, then we don't have much to count on.
>>
>> I see little risk in this myself, and would support the default changing
>> to linux-yocto in 1.0.1.
>
> Excellent point Bruce!
>
>>
>> Acked-by: Bruce Ashfield <bruce.ashfield@windriver.com>
>>
>>>
>>> Thanks,
>>>
>>> Darren Hart
>>>
>>
>
> --
> Darren Hart
> Intel Open Source Technology Center
> Yocto Project - Linux Kernel
> _______________________________________________
> poky mailing list
> poky@yoctoproject.org
> https://lists.yoctoproject.org/listinfo/poky
>



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