Re: [HMM 12/15] mm/migrate: new memory migration helper for use with device memory v4

From: Evgeny Baskakov
Date: Tue Jul 25 2017 - 18:45:21 EST


On 7/20/17 6:33 PM, Jerome Glisse wrote:

So i pushed an updated hmm-next branch it should have all fixes so far, including
something that should fix this issue. I still want to go over all emails again
to make sure i am not forgetting anything.

Cheers,
JÃrÃme

Hi Jerome,

Thanks for updating the documentation for hmm_devmem_ops.

I have an inquiry about the "fault" callback, though. The documentation says "Returns: 0 on success", but can the driver set any VM_FAULT_* flags? For instance, the driver might want to set the VM_FAULT_MAJOR flag to indicate that a heavy-weight page migration has happened on the page fault.

If that is possible, can you please update the documentation and list the flags that are permitted in the callback's return value?

Thanks!

--
Evgeny Baskakov
NVIDIA