On 4/4/23 11:33, Crystal Wood wrote:
> On Tue, 2023-04-04 at 10:55 -0400, Sean Anderson wrote:
>
>> @@ -1456,11 +1456,11 @@ static void tqm_congestion_task(struct work_struct
>> *work)
>> union qm_mc_result *mcr;
>> struct qman_cgr *cgr;
>>
>> - spin_lock_irq(&p->cgr_lock);
>> + raw_spin_lock_irq(&p->cgr_lock);
>> qm_mc_start(&p->p);
>> qm_mc_commit(&p->p, QM_MCC_VERB_QUERYCONGESTION);
>> if (!qm_mc_result_timeout(&p->p, &mcr)) {
>> - spin_unlock_irq(&p->cgr_lock);
>> + raw_spin_unlock_irq(&p->cgr_lock);
>
> qm_mc_result_timeout() spins with a timeout of 10 ms which is very
> inappropriate for a raw lock. What is the actual expected upper bound?
Hm, maybe we can move this qm_mc stuff outside cgr_lock? In most other
places they're called without cgr_lock, which implies that its usage
here is meant to synchronize against some other function.
>> dev_crit(p->config->dev, "QUERYCONGESTION timeout\n");
>> qman_p_irqsource_add(p, QM_PIRQ_CSCI);
>> return;
>> @@ -1476,7 +1476,7 @@ static void qm_congestion_task(struct work_struct
>> *work)
>> list_for_each_entry(cgr, &p->cgr_cbs, node)
>> if (cgr->cb && qman_cgrs_get(&c, cgr->cgrid))
>> cgr->cb(p, cgr, qman_cgrs_get(&rr, cgr->cgrid));
>> - spin_unlock_irq(&p->cgr_lock);
>> + raw_spin_unlock_irq(&p->cgr_lock);
>> qman_p_irqsource_add(p, QM_PIRQ_CSCI);
>> }
>
> The callback loop is also a bit concerning...
The callbacks (in .../dpaa/dpaa_eth.c and .../caam/qi.c) look OK. The
only thing which might take a bit is dpaa_eth_refill_bpools, which
allocates memory (from the atomic pool).
--Sean
