[CRIU] bug in shmem restore?

[Mike Rapoport]

On Jun 24, 2016 9:37 AM, "Andrei Vagin" <avagin at gmail.com> wrote:
>
> On Thu, Jun 23, 2016 at 10:45 PM, Mike Rapoport <mike.rapoport at gmail.com>
wrote:
> >
> > On Jun 24, 2016 4:23 AM, "Andrew Vagin" <avagin at virtuozzo.com> wrote:
> >>
> >> On Thu, Jun 23, 2016 at 11:31:04AM +0300, Mike Rapoport wrote:
> >> > Hi,
> >> >
> >> > I've been looking into reducing use of page-read  internals outside
> >> > the page-read.c and found something that seems really weird.
> >> >
> >> > If auto_dedup is enabled, the restore_shmem_content punches a hole in
> >> > the  pagemap image, but it never tries to read anything from the
> >> > parent image. Moreover, open_page_read_at does not even bother to
open
> >> > parent image in case it opens shared memory image.
> >> >
> >> > If I understand correctly, if the hole is really punched, calling
> >> > restore next time on the same set of images will fail.
> >>
> >> if you use --auto-dedup, you are going to run restore only once
> >
> > And what if I'd like to use the same checkpoint directories once more,
e.g.
> > on another host?
>
> Maybe you have to run criu without the --auto-dedup option in this case?

And what's the point of auto-dedup then?

> >
> >>   --auto-dedup          when used on dump it will deduplicate "old"
data
> >> in
> >>                         pages images of previous dump
> >>                         when used on restore, as soon as page is
restored,
> >> it
> >>                         will be punched from the image.
> >>
> >> >
> >> > Am I missing something?
> >> >
> >> > --
> >> > Sincerely yours,
> >> > Mike.
> >> > _______________________________________________
> >> > CRIU mailing list
> >> > CRIU at openvz.org
> >> > https://lists.openvz.org/mailman/listinfo/criu
> >
> >
> > _______________________________________________
> > CRIU mailing list
> > CRIU at openvz.org
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> >
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