[CRIU] [PATCH 2/3] mem: if no parent image persists, can't rely on it

[Cyrill Gorcunov]

On Tue, Apr 15, 2014 at 04:48:33PM +0400, Pavel Tikhomirov wrote:
>    It seem to me, that clear_soft_dirty function for pte in kernel is called
>    only
>    if we had explicit write to /proc/pid/clear_refs. Only after that all
>    pages will
>    become write-protected and dirty tracking realy works, if new process was
>    created between snapshots, some part of its memory can be not write
>    protected so no PF generated for this part and some soft-dirty bits not
>    set,
>    isn't it?

No, when new process created and executed -- new memory will all be marked
as soft-dirty. If new process is created with fork() then its pages will
be COW'ed and once write fault happened the page will be marked as soft
dirty as far as I remember.