Messages in this thread | | | Date | Fri, 6 May 2011 19:55:48 +0200 | From | Andrea Arcangeli <> | Subject | Re: iotop: khugepaged at 99.99% (2.6.38.X) |
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On Fri, May 06, 2011 at 10:49:45AM +0200, Thomas Sattler wrote: > > You can already run "grep threshold /proc/zoneinfo" on the system > > where you reproduced the hang the last time (the one running 2.6.38.4) > > the one with 1.5G of ram. They all should be well below 512 (so in > > theory not causing troubles because of the per-cpu stats, and with so > > few cpus it shouldn't have been such a longstanding problem anyway). > > 'grep threshold /proc/zoneinfo' returns nothing on this machine after > a reboot and before a crash. Did I tell it's a single core machine?
Hmm single core machine doesn't seem to fit my theory of per-cpu stats too well... I think it's not impossible but it should only be possible on smp and maybe it's not reproducible and probably not what you're dealing with.
The new make-it-worse-patch should help to reproduce though.
If you can "cat /proc/zoneinfo" _during_ the hang (and then run sysrq+t again to see the status, no need of sysrq+l), it'll help to try to track this down. I'll recheck your last sysrq+t once again to see if I get other ideas.
A 'cat /proc/zoneinfo' after the hang resolves itself and the system is mostly idle, will also be interesting to verify the nr_isolated_* are all zero.
Thanks, Andrea
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