Re: [PATCH] c/r: define s390-specific checkpoint-restart code

["Serge E. Hallyn" <serue@us.ibm.com>]

Quoting Oren Laadan (orenl@cs.columbia.edu):
> 
> 
> Serge E. Hallyn wrote:
> > Implement the s390 arch-specific checkpoint/restart helpers.  This
> 
> Thanks for the patch.
> 
> I will assume that the s390 specifics are correct...
> 
> > is on top of Oren Laadan's c/r code (which so far was x86_32-only)
> > submitted here: http://lkml.org/lkml/2008/12/29/38, plus two more
> > patches by Nathan Lynch to fix some 64-bit issues (see
> > https://lists.linux-foundation.org/pipermail/containers/2009-January/015313.html
> > and
> > https://lists.linux-foundation.org/pipermail/containers/2009-January/015314.html
> > ).
> 
> ckpt-v13 already has these two fixed.
> 
> > 
> > With these, I am able to checkpoint and restart simple programs as per
> > Oren's patch intro.  While on x86 I never had to freeze a single task
> > to checkpoint it, on s390 I do need to.  That is a prereq for consistent
> > snapshots (esp with multiple processes) anyway so I don't see that as
> > a problem.
> > 
> > Oren, should we be putting a byte at the front of the format to
> > specify the architecture?
> 
> If we add a field to 'struct cr_hdr_head', then we'll need arch-dependent
> code in a non-arch dependent source, to ensure that no two architectures
> choose the same value as an identifier.
> 
> Can we not use the 'machine' string fiels in 'struct cr_hdr_head' - and
> then additional classification can take place in cr_read/write_head_arch() ?

Huh, yes, I somehow missed that.

> > +#define DEBUG 1
> > +
> >  #include <linux/version.h>
> >  #include <linux/sched.h>
> >  #include <linux/ptrace.h>
> > diff --git a/checkpoint/restart.c b/checkpoint/restart.c
> > index 6b4cd75..f65a63e 100644
> > --- a/checkpoint/restart.c
> > +++ b/checkpoint/restart.c
> > @@ -8,6 +8,8 @@
> >   *  distribution for more details.
> >   */
> >  
> > +#define DEBUG 1
> > +
> >  #include <linux/version.h>
> >  #include <linux/sched.h>
> >  #include <linux/wait.h>
> > 
> 
> Probably unrelated ?

Yup.  Will send a new version inc. your changes and against
v13 later this week.

thanks,
-serge