On Tuesday, September 13, 2011 6:29:05 pm Ryan Stone wrote: > On Tue, Sep 13, 2011 at 2:36 PM, Arnaud Lacombe <lacom...@gmail.com> wrote: > > It did not crash, yet. The only downside is that after 3h30 and ~4h, > > igb(4) queues' handler started spinning infinitely, breaking network > > connectivity. > > I saw a similar issue on HEAD last week. The attached patch fix the > problem for me. The problem was that if a struct task's ta_pending > field overflows, the task will be inserted into a list when it is > already in that list, causing a cycle in the list of tasks to be run. > This causes the taskqueue thread to spin indefinitely as it looks over > the cycle again and again. > > In case the list eats the patch, it was: > > Index: sys/kern/subr_taskqueue.c > =================================================================== > --- sys/kern/subr_taskqueue.c (revision 225537) > +++ sys/kern/subr_taskqueue.c (working copy) > @@ -173,7 +173,8 @@ > * Count multiple enqueues. > */ > if (task->ta_pending) { > - task->ta_pending++; > + if (task->ta_pending < UINT16_MAX) > + task->ta_pending++; > return (0); > }
You should probably commit that. I wonder if it should be a KASSERT() also so that it outright panics on a kernel with INVARIANTS enabled so developers will go fix their code as it seems to me to likely be a bug to enqueue a task that many times. -- John Baldwin _______________________________________________ freebsd-net@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-net To unsubscribe, send any mail to "freebsd-net-unsubscr...@freebsd.org"