Re: [PATCH 1/2] bitmap: add sanity check function for find_bit()

[Russell King (Oracle)]

On Tue, Oct 25, 2022 at 10:11:51AM -0700, Yury Norov wrote:
> ARMv6 may or may not support unaligned access depending on SCTLR.U
> bit. This is what Russell was concerned about in the other email.
> As far as I understand, linux enables that feature.

However, we still support ARMv5 and ARMv4, both of which _trap_ every
unaligned access, which will make a findbit call with an unaligned
pointer using word loads painfully expensive. This is the main reason
we haven't used word loads in the findbit ops.

As mentioned, I have patches that do change that (and convert the
thing to use assembly macros to make updates much easier.)

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
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