boot time regressed a lot due to misaligned access probe

[Ben Dooks]

On 13/09/2023 01:14, Jisheng Zhang wrote:
> Hi all,
> 
> Probing one cpu for misaligned access cost about 0.06s, so it will cost
> about 3.8s on platforms with 64 CPUs, for example, milkv pioneer which
> is powered by sg2042.
> 
> I'm not sure the reason of probing misaligned access for all CPUs. If
> the HW doesn't behave as SMP from misalligned access side, then unless
> userspace processes force cpu affinity, they always suffer from this
> non-SMP pain.
> 
> So, can we only probe the boot cpu?

So a couple of ideas:

#1 is it worth adding a device-tree property to explicitly to say if
the unaligned access has been measured and known

#2 only probe one cpu in a cluster if there are multiple clusters of
cpus?

-- 
Ben Dooks				http://www.codethink.co.uk/
Senior Engineer				Codethink - Providing Genius

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