lkml.org 
[lkml]   [2017]   [Apr]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [HMM 03/15] mm/unaddressable-memory: new type of ZONE_DEVICE for unaddressable memory
On 04/23/2017 08:39 PM, John Hubbard wrote:

> Actually, MEMORY_DEVICE_PRIVATE / _PUBLIC seems like a good choice to
> me, because the memory may not remain CPU-unaddressable in the future.
> By that, I mean that I know of at least one company (ours) that is
> working on products that will support hardware-based memory coherence
> (and access counters to go along with that). If someone were to enable
> HMM on such a system, then the device memory would be, in fact, directly
> addressable by a CPU--thus exactly contradicting the "unaddressable" name.

I'm expecting similar with CCIX-like coherently attached accelerators
running within FPGAs and as discrete devices as well. Everyone and their
dog is working on hardware based coherence as a programming convenience
and so the notion of ZONE_DEVICE as it stood is going to rapidly evolve
over the next 18 months, maybe less. Short term anyway.

Jon.

\
 
 \ /
  Last update: 2017-04-25 09:09    [W:0.070 / U:0.308 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site