Re: [PATCH v11 06/10] genirq/msi-doorbell: msi_doorbell_safe

From	Auger Eric <eric.auger@redhat.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH v11 06/10] genirq/msi-doorbell: msi_doorbell_safe
Date	2016-07-22 16:10 +0200
Message-ID	<rXJjk-6SA-13@gated-at.bofh.it> (permalink)
References	<rWCWB-4qE-3@gated-at.bofh.it> <rWCWD-4qE-49@gated-at.bofh.it> <rWUTw-7mO-21@gated-at.bofh.it> <rXmmJ-81c-25@gated-at.bofh.it> <rXI3U-5Un-21@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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Hi Thomas,
On 22/07/2016 14:44, Thomas Gleixner wrote:
> On Thu, 21 Jul 2016, Auger Eric wrote:
>> On 20/07/2016 10:12, Thomas Gleixner wrote:
>>> On Tue, 19 Jul 2016, Eric Auger wrote:
>>>> +bool msi_doorbell_safe(void)
>>>> +{
>>>> +	struct irqchip_doorbell *db;
>>>> +	bool irq_remapping = true;
>>>> +
>>>> +	mutex_lock(&irqchip_doorbell_mutex);
>>>> +	list_for_each_entry(db, &irqchip_doorbell_list, next) {
>>>> +		irq_remapping &= db->info.irq_remapping;
>>>
>>> db->info.irq_remapping is set in msi_doorbell_register(). So you can keep book
>>> about that there. No need to iterate here.
>> Yes makes sense to store the info at registration time. Currently this
>> function is not in any fast path but that's cleaner from a general
>> perspective. I will need to do such iteration at un-registration though.
> 
> Two simple counter should be sufficient.
> 
>   nr_registered_bells;
>   nr_remapped_bells;

Yes definitively smarter to use counters! mental viscosity.

Thanks

Eric
> 
> ....
> 
> Thanks,
> 
> 	tglx
>

Thread

[PATCH v11 00/10] KVM PCIe/MSI passthrough on ARM/ARM64: kernel part 2/3: msi changes Eric Auger <eric.auger@redhat.com> - 2016-07-19 15:10 +0200
  [PATCH v11 02/10] genirq/msi: msi_compose wrapper Eric Auger <eric.auger@redhat.com> - 2016-07-19 15:10 +0200
  [PATCH v11 09/10] genirq/msi: map/unmap the MSI doorbells on msi_domain_alloc/free_irqs Eric Auger <eric.auger@redhat.com> - 2016-07-19 15:10 +0200
    Re: [PATCH v11 09/10] genirq/msi: map/unmap the MSI doorbells on  msi_domain_alloc/free_irqs Thomas Gleixner <tglx@linutronix.de> - 2016-07-20 11:10 +0200
      Re: [PATCH v11 09/10] genirq/msi: map/unmap the MSI doorbells on  msi_domain_alloc/free_irqs Auger Eric <eric.auger@redhat.com> - 2016-07-25 18:30 +0200
  [PATCH v11 10/10] genirq/msi: use the MSI doorbell's IOVA when requested Eric Auger <eric.auger@redhat.com> - 2016-07-19 15:10 +0200
    Re: [PATCH v11 10/10] genirq/msi: use the MSI doorbell's IOVA when  requested Thomas Gleixner <tglx@linutronix.de> - 2016-07-20 11:20 +0200
      Re: [PATCH v11 10/10] genirq/msi: use the MSI doorbell's IOVA when  requested Auger Eric <eric.auger@redhat.com> - 2016-07-25 18:40 +0200
  [PATCH v11 08/10] irqchip/gicv3-its: register the MSI global doorbell Eric Auger <eric.auger@redhat.com> - 2016-07-19 15:10 +0200
  [PATCH v11 06/10] genirq/msi-doorbell: msi_doorbell_safe Eric Auger <eric.auger@redhat.com> - 2016-07-19 15:10 +0200
    Re: [PATCH v11 06/10] genirq/msi-doorbell: msi_doorbell_safe Thomas Gleixner <tglx@linutronix.de> - 2016-07-20 10:20 +0200
      Re: [PATCH v11 06/10] genirq/msi-doorbell: msi_doorbell_safe Auger Eric <eric.auger@redhat.com> - 2016-07-21 15:40 +0200
        Re: [PATCH v11 06/10] genirq/msi-doorbell: msi_doorbell_safe Thomas Gleixner <tglx@linutronix.de> - 2016-07-22 14:50 +0200
          Re: [PATCH v11 06/10] genirq/msi-doorbell: msi_doorbell_safe Auger Eric <eric.auger@redhat.com> - 2016-07-22 16:10 +0200
  [PATCH v11 01/10] genirq/msi: export msi_get_domain_info Eric Auger <eric.auger@redhat.com> - 2016-07-19 15:10 +0200

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