Re: [PATCH v2 09/13] xen/arm: Reduce struct membank size on static shared memory

[Michal Orzel <michal.orzel@xxxxxxx>]

On 10/04/2024 13:19, Luca Fancellu wrote:
> 
> 
>>>>>
>>>>> Afterwards, create a new structure 'struct shared_meminfo' which
>>>>> has the same interface of 'struct meminfo', but requires less
>>>> I would expect some justification for selecting 32 as the max number of 
>>>> shmem banks
>>>
>>> So I have to say I picked up a value I thought was ok for the amount of 
>>> shared memory
>>> Banks, do you think it is too low? The real intention here was to decouple 
>>> the number
>>> of shared memory banks from the number of generic memory banks, and I felt 
>>> 32 was enough,
>>> but if you think it might be an issue I could bump it, or we could have a 
>>> Kconfig...
>> No need for Kconfig. 32 is enough for now but I expect a paragraph in commit 
>> msg that you select
>> 32 which should be enough for current use cases and can be bumped in the 
>> future in case there is a need.
> 
> What do you think of this proposal:
> 
> [...]
> hence the 'struct membank' won't grow in size.
> 
> Afterwards, create a new structure 'struct shared_meminfo' which
> has the same interface of 'struct meminfo', but requires less
> banks, defined by the number in NR_SHMEM_BANKS, which is 32 at the
> moment and should be enough for the current use cases, the value
> might be increased in te future if needed.
> Finally, this structure hosts also the extra information for the
> static shared memory banks.
> The fields 'bank' and 'extra' of this structure are meant to be
> [...]
reads ok

~Michal