strace lockup when tracing exec in go

[Michal Hocko]

On Thu 22-09-16 12:09:05, Mike Galbraith wrote:
> On Thu, 2016-09-22 at 11:53 +0200, Michal Hocko wrote:
> > On Thu 22-09-16 11:40:09, Mike Galbraith wrote:
> 
> > > This patch doesn't help, nor does the previous patch... but with both
> > > applied, all is well.  All you have to do now is figure out why :)
> > 
> > Ohh, I should be more explicit, this needs the mm_access part as well.
> > Sorry for not being clear enough. So the full change is
> 
> Ah.  That was gonna happen after lunch, but since you already know it
> works, I can get back to un-b0rking one of my trees.

Yeah, it should work. The testcase is running in a loop for more than
hour already and everything seems to be ok. Now the question is whether
the fix is really correct which is something for Oleg.

Also I think there is at least one more issue lurking there. Without or
without the patch I can make tracer get stuck in do_wait waiting for
task which doesn't seem to be alive anymore. I will report it separately
after this one gets resolved to not pull more confusion in.

Anyway, thanks for your time Mike!
-- 
Michal Hocko
SUSE Labs