Messages in this thread | | | Date | Thu, 18 Jul 2019 18:36:01 +0200 | From | Pavel Machek <> | Subject | Re: HMM_MIRROR has less than useful help text |
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On Thu 2019-07-18 07:25:42, Dan Williams wrote: > On Thu, Jul 18, 2019 at 4:04 AM Balbir Singh <bsingharora@gmail.com> wrote: > > > > On Wed, Jul 17, 2019 at 5:41 PM Pavel Machek <pavel@ucw.cz> 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?
I hoped patch author would fix up their code. I'm not HMM expert, he should be...
Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html [unhandled content-type:application/pgp-signature] | |