Re: CVS commit: src/sys/arch/aarch64/aarch64

[Jared McNeill <jmcneill%invisible.ca@localhost>]

I think this will have issues on some big.LITTLE configurations 
like Rockchip RK3399.

In the RK3399 case cpu[0-3] is VIPT I$ and cpu[4-5] is PIPT I$. Boot 
order of secondaries is not guaranteed so it is possible to get different 
values of aarch64_cache_vindexsize from one boot to the next.

Jared


On Thu, 2 Jul 2020, Rin Okuyama wrote:

> Module Name:	src
> Committed By:	rin
> Date:		Thu Jul  2 12:59:31 UTC 2020
>
> Modified Files:
> 	src/sys/arch/aarch64/aarch64: pmap.c
>
> Log Message:
> Set uvmexp.ncolors appropriately, which is required for some CPU
> models with VIPT icache.
>
> Otherwise, alias in virtual address results in inconsistent results,
> at least for applications that rewrite text of other process, e.g.,
> GDB for arm32.
>
> Also, this hopefully fixes other unexpected failures due to alias.
>
> Confirmed that there's no observable regression in performance;
> difference in ``time make -j8'' for GENERIC64 kernel on BCM2837
> with and without setting uvmexp.ncolors is within 0.1%.
>
> Thanks to ryo@ for discussion.
>
>
> To generate a diff of this commit:
> cvs rdiff -u -r1.80 -r1.81 src/sys/arch/aarch64/aarch64/pmap.c
>
> Please note that diffs are not public domain; they are subject to the
> copyright notices on the relevant files.