Re: [RFC PATCH] Dynamic sched domains (v0.5)

[Dinakar Guniguntala <dino@in.ibm.com>]

> >On Mon, May 02, 2005 at 07:44:05PM +1000, Nick Piggin wrote:
> 
> What are you protecting against, though? synchroinze_kernel can
> sleep, so local_irq_disable is probably the wrong thing to do as well.

Paul, any reason why code marked "####" (fn cpuset_rmdir) is under 
the dentry lock ??

	spin_lock(&cs->dentry->d_lock);
        parent = cs->parent;			####
        set_bit(CS_REMOVED, &cs->flags);	####
        if (is_cpu_exclusive(cs))
                update_cpu_domains(cs);
        list_del(&cs->sibling); /* delete my sibling from parent->children */
        if (list_empty(&parent->children))
                check_for_release(parent);
        d = dget(cs->dentry);			<----
        cs->dentry = NULL;			<----
        spin_unlock(&d->d_lock);


As far as I can see only the ones marked "<----" should be under the
dentry lock, considering the fact that it already holds the cpuset_sem
all the while.

I saw that calling update_cpu_domains with the dentry lock held,
causes it to oops with preempt turned on. (Scheduling while atomic)

	-Dinakar
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