On Tue, May 19, 2015 at 12:21:15AM +0300, Dan Carpenter wrote:
> On Mon, May 18, 2015 at 08:34:51PM +0200, Adrian Remonda wrote:
> > Fixed sparse warning: context imbalance in 'nrs_resource_put_safe' -
> > 'different lock contexts for basic block' by releasing the lock on each
> > iteration of the for loop.
> >
>
> That changelog doesn't sound correct at all. That's not a correct
> motivation or explanation.
>
> I reviewed the patch and it's likely going to cause dead locks. The code
> is trying to take the spinlock for the first pointer in the array and
> release it at the end. Now it takes the first pointer's spinlock a
> bunch of times (dead lock) and releases it once (will not happen because
> we are already dead).
>
>
Hello Dan,
thanks for the comments. The code would end up looking as next, I don't
undertand where the deadlock would be.
I know the older code would work, I just changed it to keep the lock
locked the less time as possible.
for (i = 0; i < NRS_RES_MAX; i++) {
if (pols[i] == NULL)
continue;
if (nrs == NULL) {
nrs = pols[i]->pol_nrs;
}
spin_lock(&nrs->nrs_lock);
nrs_policy_put_locked(pols[i]);
spin_unlock(&nrs->nrs_lock);
}
best regards,
Adrian
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