Bug #3627
open
ipnet taskq can outlive ipnet_stack_t (or netstack in general) and panic
0%
Description
An OI user hit a crash which looks like:
unix:die+dd () unix:trap+1799 () unix:cmntrap+e6 () unix:mutex_enter+b () ipnet:ipnet_dispatch+8c () genunix:taskq_thread+248() unix:thread_start+8 ()
Ancient memories suggest this is because an ipnet device (likely observability related) has been destroyed, and removed from the netstack, but a taskq associated with it has survived. These memories may be wildly innaccurate.
We've asked the user to gather a crash dump, hopefully a reference will be added to this bug when he does.
Updated by
Updated by Dan McDonald over 8 years ago
I'll have to look, but does ipnet_dispatch need to take a netstack that's been reference-held? Or does that cause more problems?
Updated by Dan McDonald about 8 years ago
We've found a related performance problem when ipnet observability is enabled. One possible solution should also eliminate this bug as a side-effect. I need to confirm the solution solves our performance problem first, however.
Updated by Rich Lowe about 8 years ago
Is this the perf problem ira hit where we consume a basically infinite amount of memory?
A correct fix for that should also fix this, yes ('cos the whole taskq can go away, I think).
Updated by Dan McDonald about 8 years ago
Rich Lowe wrote:
Is this the perf problem ira hit where we consume a basically infinite amount of memory?
I'd need a link to a mail, but it's highly likely yes.
A correct fix for that should also fix this, yes ('cos the whole taskq can go away, I think).
Alas, my worker-thread attempt failed to keep up, it seems. Stay tuned.