Re: HMM_MIRROR has less than useful help text

[Dan Williams]

On Thu, Jul 18, 2019 at 4:04 AM Balbir Singh <bsingharora@xxxxxxxxx> wrote:
>
> On Wed, Jul 17, 2019 at 5:41 PM Pavel Machek <pavel@xxxxxx> wrote:
> >
> > Hi!
> >
> > Commit c0b124054f9e42eb6da545a10fe9122a7d7c3f72 has very nice commit
> > message, explaining what HMM_MIRROR is and when it is
> > needed. Unfortunately, it did not make it into Kconfig help:
> >
> > CONFIG_HMM_MIRROR:
> >
> > Select HMM_MIRROR if you want to mirror range of the CPU page table of
> > a
> > process into a device page table. Here, mirror means "keep
> > synchronized".
> > Prerequisites: the device must provide the ability to write-protect
> > its
> > page tables (at PAGE_SIZE granularity), and must be able to recover
> > from
> > the resulting potential page faults.
> >
> > Could that be fixed?
> >
> > This is key information for me:
> >
> > # This is a heterogeneous memory management (HMM) process address space
> > # mirroring.
> > # This is useful for NVidia GPU >= Pascal, Mellanox IB >= mlx5 and more
> > # hardware in the future.
> >
>
> That seems like a reasonable request

Hi Pavel, care to send a patch?