i got one such message:
KERNEL: assertion (!atomic_read(&sk->sk_rmem_alloc)) failed at
net/netlink/af_netlink.c (126)
this was on a box that is DSL connected and thus gets lots of trash
packets over the wire. It is running -RT ontop of 2.6.12-rc1, and got
this message after 2 days of uptime.
There was no apparent bad side-effect after this happened - no crash, no
hung applications, no hung connections, the box is still up and running
fine. The message is not reproducible, unfortunately. Never saw this
message with 2.6.11-ish kernels on the same box.
since the locking is so different under PREEMPT_RT it may very well be
caused by PREEMPT_RT itself - but it could also be some real bug that
only triggers under PREEMPT_RT. Based on current bug trends i'd say the
likelyhood is 70% for this to be a genuine upstream bug, and 30% for
this to be a PREEMPT_RT artifact. (These days most PREEMPT_RT artifacts
get detected by PREEMPT_RT's own debugging features - and all of them
were enabled on this box. Due to its preemption model, PREEMPT_RT is
pretty good at catching races that are near-impossible to trigger on the
stock kernel. It already caught more than a dozen such upstream races in
various kernel subsystems.)
Ingo
|