On Tue, 2014-03-04 at 15:55 -0800, Florian Fainelli wrote: > Hi all, > > I am seeing the following RCU stalls messages appearing on an ARMv7 > 4xCPUs system running 3.14-rc4: > > [ 42.974327] INFO: rcu_sched detected stalls on CPUs/tasks: > [ 42.979839] (detected by 0, t=2102 jiffies, g=4294967082, > c=4294967081, q=516) > [ 42.987169] INFO: Stall ended before state dump start > > this is happening under the following conditions: > > - the attached bumper.c binary alters various kernel thread priorities > based on the contents of bumpup.cfg and > - malloc_crazy is running from a NFS share > - malloc_crazy.c is running in a loop allocating chunks of memory but > never freeing it > > when the priorities are altered, instead of getting the OOM killer to > be invoked, the RCU stalls are happening. Taking NFS out of the > equation does not allow me to reproduce the problem even with the > priorities altered. > > This "problem" seems to have been there for quite a while now since I > was able to get 3.8.13 to trigger that bug as well, with a slightly > more detailed RCU debugging trace which points the finger at kswapd0. > > You should be able to get that reproduced under QEMU with the > Versatile Express platform emulating a Cortex A15 CPU and the attached > files. > > Any help or suggestions would be greatly appreciated. Thanks! Do you have a more complete trace, including stack traces ? -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>