On Thu, 2011-04-28 at 20:21 +0100, Mel Gorman wrote: > On Thu, Apr 28, 2011 at 01:30:36PM -0500, James Bottomley wrote: > > > Way hey, cgroups are also in the mix. How jolly. > > > > > > Is systemd a common element of the machines hitting this bug by any > > > chance? > > > > Well, yes, the bug report is against FC15, which needs cgroups for > > systemd. > > > > Ok although we do not have direct evidence that it's the problem yet. A > broken shrinker could just mean we are also trying to aggressively > reclaim in cgroups. > > > > The remaining traces seem to be follow-on damage related to the three > > > issues of "shrinkers are bust in some manner" causing "we are not > > > getting over the min watermark" and as a side-show "we are spending lots > > > of time doing something unspecified but unhelpful in cgroups". > > > > Heh, well find a way for me to verify this: I can't turn off cgroups > > because systemd then won't work and the machine won't boot ... > > > > Same testcase, same kernel but a distro that is not using systemd to > verify if cgroups are the problem. Not ideal I know. When I'm back > online Tuesday, I'll try reproducing this on a !Fedora distribution. In > the meantime, the following untested hatchet job might spit out > which shrinker we are getting stuck in. It is also breaking out of > the shrink_slab loop so it'd even be interesting to see if the bug > is mitigated in any way. Actually, talking to Chris, I think I can get the system up using init=/bin/bash without systemd, so I can try the no cgroup config. > diff --git a/mm/vmscan.c b/mm/vmscan.c > index c74a501..ed99104 100644 In the mean time, this patch produces: (that's nothing ... apparently the trace doesn't activate when kswapd goes mad). James -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>