Re: [PATCH for-4.18 v5] xen/pdx: Make CONFIG_PDX_COMPRESSION a common Kconfig option

[Julien Grall <julien@xxxxxxx>]

On 06/10/2023 15:44, Andrew Cooper wrote:
> From: Alejandro Vallejo <alejandro.vallejo@xxxxxxxxx>
>
> Adds a new compile-time flag to allow disabling PDX compression and
> compiles out compression-related code/data. It also shorts the pdx<->pfn
> conversion macros and creates stubs for masking functions.
>
> While at it, removes the old arch-defined CONFIG_HAS_PDX flag.  Despite the
> illusion of choice, it was not optional.
>
> There are ARM and PPC platforms with sparse RAM banks - leave compression
> active by default there.  OTOH, there are no known production x86 systems with
> sparse RAM banks, so disable compression.  This decision can be revisited if
> such a platform comes along.
(Process remarks rather than the code itself)

Jan is away this week so I want to make sure this doesn't go in without 
him having a say.
While I don't particularly care about the approach taken for x86, Jan 
voiced concerned with this approach and so far I didn't see any 
conclusion. If there is any, then please point me to them.
For the record, the objections from Jan are in [1]. If we want to ignore 
them, then I think we need a vote. Possibly only from the x86 folks (?).
> Signed-off-by: Alejandro Vallejo <alejandro.vallejo@xxxxxxxxx>
> Reviewed-by: Julien Grall <jgrall@xxxxxxxxxx>
Cheers,

[1] b0296908-5081-5d34-8487-b8293eee97ca@xxxxxxxx

--
Julien Grall