Re: [RFC PATCH v4 5/6] drivers/migrate_offload: add DMA batch copy driver (dcbm)

Huang, Ying
2026-03-24T08:11:03Z

Hi, Shivank,

Shivank Garg <shivankg@amd.com> writes:

> Simple DMAEngine based driver that uses memcpy channels to batch-copy
> folios during page migration. Primarily for testing the copy offload
> infrastructure.
>
> When DMA fails the callback returns an error and the migration path
> falls back to per-folio CPU copy.
>
> Sysfs interface under /sys/kernel/dcbm/:
> offloading - enable/disable DMA offload
> nr_dma_chan - max number of DMA channels to use
> folios_migrated - folios copied via DMA
> folios_failures - fallback count

How about placing the sysfs interface under /sys/module/dcbm/? We will
have multiple migrator implementations in the future, so dcbm behaves
more like a driver, right?

---
Best Regards,
Huang, Ying

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