Re: [PATCH 10/27] mips, smpboot: Use generic SMP booting infrastructure

From: Srivatsa S. Bhat
Date: Sun Jun 03 2012 - 07:49:08 EST


On 06/03/2012 01:55 PM, Yong Zhang wrote:

> On Fri, Jun 01, 2012 at 02:42:32PM +0530, Srivatsa S. Bhat wrote:
>> Convert mips to use the generic framework to boot secondary CPUs.
>>
>> Notes:
>> 1. The boot processor was setting the secondary cpu in cpu_online_mask!
>> Instead, leave it up to the secondary cpu (... and it will be done by the
>> generic code now).
>>
>> 2. Make the boot cpu wait for the secondary cpu to be set in cpu_online_mask
>> before returning.
>
> We don't need to wait for both cpu_callin_map (The code above yours)
> any more.


Yes, I noticed that while writing the patch. But then, I thought of cleaning
up the hundreds of callin/callout/commenced maps in various architectures and
bringing them out into core code in a later series, and clean this up at that time..
I didn't want to do too many invasive changes all at one-shot.

But I guess for this particular case of mips, I can get rid of the wait for
cpu_callin_map in this patchset itself. I'll update this patch with that change.

Thanks!

>
>>
>> 3. Don't enable interrupts in cmp_smp_finish() and vsmp_smp_finish().
>> Do it much later, in generic code.
>
> Hmmm... the bad thing is that some board enable irq more early than
> ->smp_finish(), I have sent patches for that (by moving irq enable
> to smp_finish() and delaying smp_finish()).
> Please check patch#0001~patch#0004 in
> http://marc.info/?l=linux-mips&m=133758022710973&w=2
>
>>
>> 4. In synchronise_count_slave(), use local_save_flags() instead of
>> local_irq_save() because irqs are still disabled.
>
> We can just remove local_irq_save()/local_irq_restore() like:
> http://marc.info/?l=linux-mips&m=133758046211043&w=2
>


So what is the status of those patches? Has anyone picked them up?

I could rebase this patch on top of yours, or better yet, if your
patches haven't been picked up yet, I could include them in this
patchset itself to avoid too many dependencies on external patches.

What do you say?

Regards,
Srivatsa S. Bhat

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