Re: [ANNOUNCE] v5.14-rc4-rt4

[Jens Axboe]

On 8/4/21 10:47 AM, Sebastian Andrzej Siewior wrote:
> On 2021-08-04 10:22:59 [-0600], Jens Axboe wrote:
>>
>> In that regard, I do still consider those patches out-of-tree, which
>> they are. And while I'm more sympathetic to them compared to other
>> out-of-tree code as there's a long term plan to get it all in, it's
>> still out-of-tree. Best solution here is probably to just carry that
>> particular change in the RT patchset for now.
> 
> So today in the morning I learned that there is a memory allocation in
> an IRQ-off section and now, a patch later, it is almost gone. So that
> makes me actually happy :)

1 out of 2 is better than 0 ;-)

> The spin_lock_irq() vs local_irq_disable() + spin_lock() is documented
> in Documentation/locking/locktypes.rst.
> That said I have no problem by carrying that patch in the RT-patchset
> and revisit it later.

Right, I suspect that was added as a pre RT patch dump at some point.
It's a newer thing. Is it actually possible to set PREEMPT_RT in the
mainline kernel? Looks like it depends on ARCH_SUPPORTS_RT and nobody
sets that.

So I agree that just carrying your solution in the RT patchset is fine
for now, we can revisit later.

-- 
Jens Axboe