| | Date | Thu, 8 Mar 2007 23:22:33 +0530 | | From | Srivatsa Vaddagiri <> | | Subject | Re: [PATCH 3/7] containers (V7): Add generic multi-subsystem API to containers |
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On Mon, Feb 12, 2007 at 12:15:24AM -0800, menage@google.com wrote: > +static struct container_group *find_container_group( > + struct container_group *oldcg, struct container *cont) > +{ > + struct container_group *res; > + struct container_subsys *ss; > + int h = cont->hierarchy; > + int i; > + > + BUG_ON(oldcg->container[h] == cont); > + /* First see if we already have a container group that matches > + * the desired set */ > + spin_lock(&container_group_lock);
I think this should be spin_lock_irq().
I have been bitten by lockdep warning in the rcfs patchs. But I think they should apply here as well.
Essentially, container_task_count() is called from cpuset.c after doing write_lock_irq(tasklist_lock). This creates the dependency:
tasklist_lock (irqs disabled) -> container_group_lock
However in above function, find_container_group (and several other functions) we take container_group_lock w/o blocking interrupts. An interrupt handler now trying to take tasklist_lock will cause a deadlock.
-- Regards, vatsa - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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