This is the mail archive of the
mailing list for the GDB project.
Re: [RFC][PATCH][PR 18376] gdb: Add process record and replay support for s390.
- From: "Ulrich Weigand" <uweigand at de dot ibm dot com>
- To: koriakin at 0x04 dot net (Marcin KoÅcielnicki)
- Cc: gdb-patches at sourceware dot org
- Date: Fri, 30 Oct 2015 13:06:08 +0100 (CET)
- Subject: Re: [RFC][PATCH][PR 18376] gdb: Add process record and replay support for s390.
- Authentication-results: sourceware.org; auth=none
Marcin KoÃ?cielnicki <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:
> >> 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).
Dr. Ulrich Weigand
GNU/Linux compilers and toolchain