Re: [PATCH 0/7] Accelerate page migration with batch copying and hardware offload

[David Hildenbrand (Arm)]

On 5/12/26 04:35, Huang, Ying wrote:
> "David Hildenbrand (Arm)" <david@xxxxxxxxxx> writes:
> 
>> On 4/28/26 17:50, Shivank Garg wrote:
>>> This is the fifth RFC of the patchset to enhance page migration by
> 
> [snip]
>>
>>>
>>> 3. Per-caller offload selection: Today eligibility is by migrate_reason
>>>    only. Some are latency-tolerant, others may be not. Is reason the
>>>    right granularity, or do we want a per-caller hint?
>>
>> Isn't it sufficient to just do it based on the #folios or sth like that?
>>
>> If someone migrates a handful of folios, latency is likely more important (and
>> batching less beneficial).
>>
>> I'd assume when migrating many folios, batching could just always be done. Or
>> what's the concern?
> 
> IIUC, for callers like migrate_pages syscall, it's possible that almost all
> folios of a process are passed to migrate_pages().  However, I think that
> we still need to keep the folio inaccessible time reasonable.

Wouldn't we still want to process them in batches, only affecting folios in a
batch at one point in time, not the whole address space?

-- 
Cheers,

David