Re: [PATCH v3 03/16] arm64: Allow IPIs to be handled as normal interrupts

Valentin Schneider
2020-10-19T16:00:15Z

Hi,

On 19/10/20 16:43, Vincent Guittot wrote:
> On Mon, 19 Oct 2020 at 15:04, Marc Zyngier <maz@kernel.org> wrote:
>> Since you are running perf, can you spot where the overhead occurs?
>
> hmm... Difficult to say because tracing the bench decreases a lot the
> result. I have pasted the perf reports.
>

<snip>

> I have only put symbol with overhead above 1%
>
> so _raw_spin_unlock_irq, schedule and __schedule seem the most
> impacted but i can't get any conclusion
>

AFAICT on TX2 you should be able to run these and get some more details
within IRQ-disabled regions:

https://lore.kernel.org/linux-arm-kernel/20200924110706.254996-1-alexandru.elisei@arm.com/

(they should be on linux-next)

> I can sent you perf.data files if you want
>
>
>>
>> Thanks,
>>
>> M.
>> --
>> Jazz is not dead. It just smells funny...