Android 2.3 / 2.3.4 Gingerbread Dual Core support

[macdorson]

Hi,

The Kernel has SMP support.
Do the Android Middleware - Gingerbread (2.3/2.3.4) or
earlier releases has SMP or dual core support ??


Thanks
Macdorson

[Alpha Bao]

Supported, just open smp on kernel.

> --
> You received this message because you are subscribed to the Google Groups "android-platform" group.
> To post to this group, send email to android-...@googlegroups.com.
> To unsubscribe from this group, send email to android-platfo...@googlegroups.com.
> For more options, visit this group at http://groups.google.com/group/android-platform?hl=en.
>

[David Turner]

On Wed, Jun 8, 2011 at 11:26 AM, macdorson <mohamme...@gmail.com> wrote:

Hi,

         The Kernel has SMP support.
         Do the Android Middleware - Gingerbread (2.3/2.3.4) or
earlier releases has SMP or dual core support ??

 

No, proper multi-core support was only added in Honeycomb. This requires careful changes in the C library, Dalvik and a few other parts of the platform.

[koba]

Gingerbread has build flag TARGET_CPU_SMP.
Is this not enough?

On Jun 9, 4:29 am, David Turner <di...@android.com> wrote:

[Dianne Hackborn]

No a build flag is not enough.

--
Dianne Hackborn
Android framework engineer
hac...@android.com

Note: please don't send private questions to me, as I don't have time to provide private support, and so won't reply to such e-mails.  All such questions should be posted on public forums, where I and others can see and answer them.

[Apoorva Iyer]

Hi,

Im curious about this thread, because from what I gather by reading this, Gingerbread and Froyo dont properly support Multi-core processors. Does this imply that Manufacturers are shipping Multi-core hardware on software that doesn't completely support it yet?

Regards

[Dianne Hackborn]

I don't know what manufacturers are shipping.  3.0 comes from the GB code which is modified to support SMP, so it's not like it isn't possible to do.

[David Turner]

On Fri, Jun 10, 2011 at 3:36 AM, koba <tetsu...@gmail.com> wrote:

Gingerbread has build flag TARGET_CPU_SMP.
Is this not enough?

Absolutely not. We started working on SMP support in Gingerbread (or was it Froyo), but the code was not ready at release time, so this platform is still missing critical changes that are in Honeycomb.

[David Turner]

On Fri, Jun 10, 2011 at 6:54 AM, Apoorva Iyer <apoorv...@gmail.com> wrote:

Hi,

Im curious about this thread, because from what I gather by reading this, Gingerbread and Froyo dont properly support Multi-core processors. Does this imply that Manufacturers are shipping Multi-core hardware on software that doesn't completely support it yet?

We don't have the details. It is highly likely that they performed various modifications to the system to support multi-core.

A very common trick is to restrict all threads of the same process to run on a single core

(this can actually result in better performance than the opposite in certain cases).

[Adam Jiang]

2011/6/11 David Turner <di...@android.com>:

>
>
> On Fri, Jun 10, 2011 at 3:36 AM, koba <tetsu...@gmail.com> wrote:
>>
>> Gingerbread has build flag TARGET_CPU_SMP.
>> Is this not enough?
>>
> Absolutely not. We started working on SMP support in Gingerbread (or was it
> Froyo), but the code was not ready at release time, so this platform is
> still missing critical changes that are in Honeycomb.
>>

What are those changes? Is it possible to do a backport from HC to GB?
Any code/doc could be reference?

/Adam