Re: [RFC 0/3] Pin page control subsystem

[Minchan Kim <minchan@kernel.org>]

Hi Christoph,

On Wed, Aug 14, 2013 at 04:36:44PM +0000, Christoph Lameter wrote:
> On Wed, 14 Aug 2013, Minchan Kim wrote:
> 
> > On Tue, Aug 13, 2013 at 04:21:30PM +0000, Christoph Lameter wrote:
> > > On Tue, 13 Aug 2013, Minchan Kim wrote:
> > >
> > > > VM sometime want to migrate and/or reclaim pages for CMA, memory-hotplug,
> > > > THP and so on but at the moment, it could handle only userspace pages
> > > > so if above example subsystem have pinned a some page in a range VM want
> > > > to migrate, migration is failed so above exmaple couldn't work well.
> > >
> > > Dont we have the mmu_notifiers that could help in that case? You could get
> > > a callback which could prepare the pages for migration?
> >
> > Now I'm not familiar with mmu_notifier so please could you elaborate it
> > a bit for me to dive into that?
> 
> Add a notifier callback for unpinning pages to the mmu notifier subsystem
> and then your drivers could register with the subsystem to get
> notifications when migration needs to occur etc.
> 

When I look API of mmu_notifier, it has mm_struct so I guess it works
for only user process. Right?
If so, I need to register it without user conext because zram, zswap
and zcache works for only kernel side.

-- 
Kind regards,
Minchan Kim

--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org.  For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>