On 3/6/25 20:24, Mika Penttilä wrote:
> Hi,
>
> On 3/6/25 06:42, Balbir Singh wrote:
> ...
>
>>
>> /*
>> * The only time there is no vma is when called from
>> @@ -728,15 +1000,47 @@ static void __migrate_device_pages(unsigned long *src_pfns,
>> migrate->pgmap_owner);
>> mmu_notifier_invalidate_range_start(&range);
>> }
>> - migrate_vma_insert_page(migrate, addr, newpage,
>> +
>> + if ((src_pfns[i] & MIGRATE_PFN_COMPOUND) &&
>> + (!(dst_pfns[i] & MIGRATE_PFN_COMPOUND))) {
>> + nr = HPAGE_PMD_NR;
>> + src_pfns[i] &= ~MIGRATE_PFN_COMPOUND;
>> + src_pfns[i] &= ~MIGRATE_PFN_MIGRATE;
>> + goto next;
>> + }
>> +
>> + migrate_vma_insert_page(migrate, addr, &dst_pfns[i],
>> &src_pfns[i]);
>> - continue;
>> + goto next;
>> }
>>
>> newfolio = page_folio(newpage);
>> folio = page_folio(page);
>> mapping = folio_mapping(folio);
>>
>> + /*
>> + * If THP migration is enabled, check if both src and dst
>> + * can migrate large pages
>> + */
>> + if (thp_migration_supported()) {
>> + if ((src_pfns[i] & MIGRATE_PFN_MIGRATE) &&
>> + (src_pfns[i] & MIGRATE_PFN_COMPOUND) &&
>> + !(dst_pfns[i] & MIGRATE_PFN_COMPOUND)) {
>> +
>> + if (!migrate) {
>> + src_pfns[i] &= ~(MIGRATE_PFN_MIGRATE |
>> + MIGRATE_PFN_COMPOUND);
>> + goto next;
>> + }
>> + src_pfns[i] &= ~MIGRATE_PFN_MIGRATE;
>
> This looks strange as is but patch 08 changes this to split and then
> migrate.
Yes, in the series at patch 4/11 split migration is not supported. That support
needs additional changes to be fully supported and comes in later.
>
>
>> + } else if ((src_pfns[i] & MIGRATE_PFN_MIGRATE) &&
>> + (dst_pfns[i] & MIGRATE_PFN_COMPOUND) &&
>> + !(src_pfns[i] & MIGRATE_PFN_COMPOUND)) {
>> + src_pfns[i] &= ~MIGRATE_PFN_MIGRATE;
>
> Should there be goto next; or similar here also, we are not migrating
> this src?
>
Yes, will do, but generally it just falls through, but the additional checks below
are not needed.
Thanks for the review!
Balbir
