Re: [RFC 4/7] mm: factor out madvise's core functionality

[Oleksandr Natalenko]

Hi.

On Tue, May 21, 2019 at 08:50:00AM +0200, Michal Hocko wrote:
> On Tue 21-05-19 08:36:28, Oleksandr Natalenko wrote:
> [...]
> > Regarding restricting the hints, I'm definitely interested in having
> > remote MADV_MERGEABLE/MADV_UNMERGEABLE. But, OTOH, doing it via remote
> > madvise() introduces another issue with traversing remote VMAs reliably.
> > IIUC, one can do this via userspace by parsing [s]maps file only, which
> > is not very consistent, and once some range is parsed, and then it is
> > immediately gone, a wrong hint will be sent.
> > 
> > Isn't this a problem we should worry about?
> 
> See http://lkml.kernel.org/r/20190520091829.GY6836@xxxxxxxxxxxxxx

Oh, thanks for the pointer.

Indeed, for my specific task with remote KSM I'd go with map_files
instead. This doesn't solve the task completely in case of traversal
through all the VMAs in one pass, but makes it easier comparing to a
remote syscall.

-- 
  Best regards,
    Oleksandr Natalenko (post-factum)
    Senior Software Maintenance Engineer