Re: [RFC][PATCH][PR 18376] gdb: Add process record and replay support for s390.

["Ulrich Weigand" <uweigand@de.ibm.com>]

Marcin KoÅcielnicki <koriakin at 0x04 dot net> wrote:
> On 30/10/15 11:39, Ulrich Weigand wrote:
> > This sounds find to me.   There may be an issue (which we recently found on
> > PowerPC as well) with very recent glibc versions that attempt to use
> > transactions for lock elision.  If every transactional instruction will
> > cause process record to abort, this may happen during many common glibc
> > routines in that case.  A simple way to fix this might be to accept at
> > least TBEGIN for process recording, assuming that it will always fail.
> > (That failure ought to trigger the non-transactional fallback in glibc.)
> 
> I'll do that, but I have no way of testing it - I only have access to a 
> z196 machine.

For working on GDB, you should be able to get access to a z13 guest here:
http://dcc4z.syr.edu/

> >> The gdb.reverse testsuite passes after this commit on both s390-linux and
> >> s390x-linux (except for the waitpid test, as mentioned in the record fixes
> >> thread).
> >
> > Excellent.  From the follow-on discussions on the list, it seems the
> > waitpid issue is now also resolved?
> 
> Well, the test passes now, though there's definitely still a bug 
> somewhere in fork handling (BZ 19187).

Ah, OK.

Bye,
Ulrich

-- 
  Dr. Ulrich Weigand
  GNU/Linux compilers and toolchain
  Ulrich.Weigand@de.ibm.com