----- Original Message ----- > From: "Dave Jones" <davej@xxxxxxxxxxxxxxxxx> > To: "Jan Stancek" <jstancek@xxxxxxxxxx> > Cc: trinity@xxxxxxxxxxxxxxx > Sent: Saturday, 10 September, 2016 3:46:30 AM > Subject: Re: [bug] child processes stall forever and don't get killed > > On Fri, Sep 09, 2016 at 10:16:17AM -0400, Jan Stancek wrote: > > > > > I'm seeing more the opposite of what commit above says. Most CPUs > > > > are idle, because N-1 children are stuck in recv/read/... > > > > and last child manages to keep going. Then by a chance it also hits > > > > a syscall that doesn't complete and system stays idle > > > > (after ~hour I gave up waiting). > > > > > > Need to think some more on this, but as a quick guess... > > > try replacing the <= BEFORE with < BEFORE > > > > I've started new test with patch above reverted and that looks good > > so far. No stalls after 1 hour. Previously it stalled after ~20-30 > > minutes. I noticed that when syscall stat messages (those which show > > number of iteration) stopped appearing. > > Ok, I committed that, but with a minor change to widen how long we spend > in BEFORE state slightly. I doubt that part will have a negative effect, > but holler if it does.. I applied this patch and I haven't seen stalls in over-night test. Thanks, Jan > > > > I'll try and find some time to look into this soon. I'm surprised I > > > haven't also seen it happen though. How many CPUs & how many child > > > processes ? > > > > Anywhere from 2-8 CPUs, 8-32 children on x86_64, ppc64le and s390x > > systems (RHEL7.3 Beta). It happened usually within 20-30 minutes. > > Weird. I'm doing 24/7 runs on one quad core and didn't hit it. > But I wonder if I was just fortunate enough that I had some children > always making progress even if N-1 were stuck. > > Dave > > -- To unsubscribe from this list: send the line "unsubscribe trinity" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
