On Mon, 4 Jan 2010 16:52:25 +0100
Oleg Nesterov o...@redhat.com wrote:
Hi!
We have some strange problems with utrace on s390, and so far this _looks_
like a s390 problem.
Looks like, on any CPU user_enable_single_step() does not work until at
least one thread with per_info.single_step =
On 01/04, Oleg Nesterov wrote:
IOW. I think this problem is minor and probably can be ignored,
Or may be not...
Even if the child is not killed by SIGTRAP, it can get a lot of
unnecessary traps.
To verify, I did another trivial patch (below), and the test
case from
The PER control registers only get reloaded on task switch. Can you test
if this patch fixes your problem?
Long ago when I first worked with David Wilder on s390 arch code,
I remember we made this change. It seems to have been forgotten
in the later rounds of reworking and merging.
Thanks,
This probably means that copy_process()-user_disable_single_step()
is not enough to clear the this task wants single-stepping copied
from parent.
I would suspect s390's TIF_SINGLE_STEP flag here. That flag means a
single-step trap occurred. This is what causes do_single_step to be
called
