Re: [Dmtcp-forum] random mismatch motherpid and tls_pid, tls_tid

[Nausca <na...@ca...>]

Hi
I believe when restart process in the very early phase, there is no libc 
available.
so I modify my code to:

init_STATIC_TLS_TID_OFFSET=STATIC_TLS_TID_OFFSET();

in mtcp_init function,
and use the static variable 'init_STATIC_TLS_TID_OFFSET' instead.
then restart won't need to call 'gnu_get_libc_version()'

thanks.
nausca.

----- Original Message ----- 
From: "Kapil Arya" <ka...@cc...>
To: "Gene Cooperman" <ge...@cc...>
Cc: "Nausca Hsu" <na...@ca...>; <dmt...@li...>
Sent: Friday, March 11, 2011 9:53 AM
Subject: Re: [Dmtcp-forum] random mismatch motherpid and tls_pid, tls_tid


On Thu, Mar 10, 2011 at 12:52 AM, Gene Cooperman <ge...@cc...> wrote:
> Hi Nausca,
> Thanks for the clarification. I wrote a preliminary suggestion and
> have now checked with Kapil to confirm some details. Below, we describe
> how you can modify the DMTCP source (based on svn revision 929) so that
> you can compile the DMTCP binaries (dmtcp_checkpoint, dmtcp_restart, etc.)
> on any machine and run them on any other machine. The binaries will
> run independently of the glibc version and kernel version of the machine
> on which they were compiled.
>
> We are also working on a new release in the next few days. The new
> release should incorporate the changes to DMTCP described below. So, you
> can wait for the release, or try out the changes now. If you try the
> changes now, could you confirm for us that these fix the problem?
> The changes are to svn revision 929 (current as of this writing).
>
> The compile-time dependencies seem to occur in four ways:
>
> A. mtcp/mtcp.c: __GLIBC_PREREQ
> There was an occurence of: #if __GLIBC_PREREQ (2,12)
> in earlier svn revisions. This has gone away in revision 929 and should
> no longer be a problem for you. We compute our information dynamically
> at runtime. We do compare the dynamic answer with a statically
> compiled answer. But if they disagree, we now proceed with the
> dynamically computed version and issue a warning about the disagreement.
> You can safely ignore any warning we produce.

DMTCP has been updated to use gnu_get_libc_version at most places. The
only significant ones are in dmtcp/src/miscwrappers.cpp around
SYS_{accept4,inotify_init,inotify_init1,epoll_create,epoll_create1}.
They are needed for proper compilation as the SYS_* is not defined in
earlier versions.