From: Julien Thierry <julien.thierry@arm.com>
To: Marc Zyngier <marc.zyngier@arm.com>,
linux-arm-kernel@lists.infradead.org,
kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org
Cc: "Raslan, KarimAllah" <karahmed@amazon.de>,
"Saidi, Ali" <alisaidi@amazon.com>
Subject: Re: [PATCH v2 1/9] KVM: arm/arm64: vgic: Add LPI translation cache definition
Date: Wed, 12 Jun 2019 09:49:53 +0100 [thread overview]
Message-ID: <37a7411c-e7e0-e601-b88b-c12e8ebf9861@arm.com> (raw)
In-Reply-To: <54c8547a-51fb-8ae5-975f-261d3934221a@arm.com>
On 12/06/2019 09:16, Julien Thierry wrote:
> Hi Marc,
>
> On 11/06/2019 18:03, Marc Zyngier wrote:
[...]
>> +
>> +void vgic_lpi_translation_cache_init(struct kvm *kvm)
>> +{
>> + struct vgic_dist *dist = &kvm->arch.vgic;
>> + unsigned int sz;
>> + int i;
>> +
>> + if (!list_empty(&dist->lpi_translation_cache))
>> + return;
>> +
>> + sz = atomic_read(&kvm->online_vcpus) * LPI_DEFAULT_PCPU_CACHE_SIZE;
>> +
>> + for (i = 0; i < sz; i++) {
>> + struct vgic_translation_cache_entry *cte;
>> +
>> + /* An allocation failure is not fatal */
>> + cte = kzalloc(sizeof(*cte), GFP_KERNEL);
>> + if (WARN_ON(!cte))
>> + break;
>> +
>> + INIT_LIST_HEAD(&cte->entry);
>> + list_add(&cte->entry, &dist->lpi_translation_cache);
>
> Going through the series, it looks like this list is either empty
> (before the cache init) or has a fixed number
> (LPI_DEFAULT_PCPU_CACHE_SIZE * nr_cpus) of entries. And the list never
> grows nor shrinks throughout the series, so it seems odd to be using a
> list here.
>
> Is there a reason for not using a dynamically allocated array instead of
> the list? (does list_move() provide a big perf advantage over swapping
> the data from one array entry to another? Or is there some other
> facility I am missing?
>
Scratch that, I realized having the list makes it easier to implement
the LRU policy later in the series.
--
Julien Thierry
WARNING: multiple messages have this Message-ID (diff)
From: Julien Thierry <julien.thierry@arm.com>
To: Marc Zyngier <marc.zyngier@arm.com>,
linux-arm-kernel@lists.infradead.org,
kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org
Cc: "Raslan, KarimAllah" <karahmed@amazon.de>,
"Saidi, Ali" <alisaidi@amazon.com>
Subject: Re: [PATCH v2 1/9] KVM: arm/arm64: vgic: Add LPI translation cache definition
Date: Wed, 12 Jun 2019 09:49:53 +0100 [thread overview]
Message-ID: <37a7411c-e7e0-e601-b88b-c12e8ebf9861@arm.com> (raw)
In-Reply-To: <54c8547a-51fb-8ae5-975f-261d3934221a@arm.com>
On 12/06/2019 09:16, Julien Thierry wrote:
> Hi Marc,
>
> On 11/06/2019 18:03, Marc Zyngier wrote:
[...]
>> +
>> +void vgic_lpi_translation_cache_init(struct kvm *kvm)
>> +{
>> + struct vgic_dist *dist = &kvm->arch.vgic;
>> + unsigned int sz;
>> + int i;
>> +
>> + if (!list_empty(&dist->lpi_translation_cache))
>> + return;
>> +
>> + sz = atomic_read(&kvm->online_vcpus) * LPI_DEFAULT_PCPU_CACHE_SIZE;
>> +
>> + for (i = 0; i < sz; i++) {
>> + struct vgic_translation_cache_entry *cte;
>> +
>> + /* An allocation failure is not fatal */
>> + cte = kzalloc(sizeof(*cte), GFP_KERNEL);
>> + if (WARN_ON(!cte))
>> + break;
>> +
>> + INIT_LIST_HEAD(&cte->entry);
>> + list_add(&cte->entry, &dist->lpi_translation_cache);
>
> Going through the series, it looks like this list is either empty
> (before the cache init) or has a fixed number
> (LPI_DEFAULT_PCPU_CACHE_SIZE * nr_cpus) of entries. And the list never
> grows nor shrinks throughout the series, so it seems odd to be using a
> list here.
>
> Is there a reason for not using a dynamically allocated array instead of
> the list? (does list_move() provide a big perf advantage over swapping
> the data from one array entry to another? Or is there some other
> facility I am missing?
>
Scratch that, I realized having the list makes it easier to implement
the LRU policy later in the series.
--
Julien Thierry
_______________________________________________
kvmarm mailing list
kvmarm@lists.cs.columbia.edu
https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
WARNING: multiple messages have this Message-ID (diff)
From: Julien Thierry <julien.thierry@arm.com>
To: Marc Zyngier <marc.zyngier@arm.com>,
linux-arm-kernel@lists.infradead.org,
kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org
Cc: "Raslan, KarimAllah" <karahmed@amazon.de>,
"Saidi, Ali" <alisaidi@amazon.com>
Subject: Re: [PATCH v2 1/9] KVM: arm/arm64: vgic: Add LPI translation cache definition
Date: Wed, 12 Jun 2019 09:49:53 +0100 [thread overview]
Message-ID: <37a7411c-e7e0-e601-b88b-c12e8ebf9861@arm.com> (raw)
In-Reply-To: <54c8547a-51fb-8ae5-975f-261d3934221a@arm.com>
On 12/06/2019 09:16, Julien Thierry wrote:
> Hi Marc,
>
> On 11/06/2019 18:03, Marc Zyngier wrote:
[...]
>> +
>> +void vgic_lpi_translation_cache_init(struct kvm *kvm)
>> +{
>> + struct vgic_dist *dist = &kvm->arch.vgic;
>> + unsigned int sz;
>> + int i;
>> +
>> + if (!list_empty(&dist->lpi_translation_cache))
>> + return;
>> +
>> + sz = atomic_read(&kvm->online_vcpus) * LPI_DEFAULT_PCPU_CACHE_SIZE;
>> +
>> + for (i = 0; i < sz; i++) {
>> + struct vgic_translation_cache_entry *cte;
>> +
>> + /* An allocation failure is not fatal */
>> + cte = kzalloc(sizeof(*cte), GFP_KERNEL);
>> + if (WARN_ON(!cte))
>> + break;
>> +
>> + INIT_LIST_HEAD(&cte->entry);
>> + list_add(&cte->entry, &dist->lpi_translation_cache);
>
> Going through the series, it looks like this list is either empty
> (before the cache init) or has a fixed number
> (LPI_DEFAULT_PCPU_CACHE_SIZE * nr_cpus) of entries. And the list never
> grows nor shrinks throughout the series, so it seems odd to be using a
> list here.
>
> Is there a reason for not using a dynamically allocated array instead of
> the list? (does list_move() provide a big perf advantage over swapping
> the data from one array entry to another? Or is there some other
> facility I am missing?
>
Scratch that, I realized having the list makes it easier to implement
the LRU policy later in the series.
--
Julien Thierry
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2019-06-12 8:49 UTC|newest]
Thread overview: 118+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-11 17:03 [PATCH v2 0/9] KVM: arm/arm64: vgic: ITS translation cache Marc Zyngier
2019-06-11 17:03 ` Marc Zyngier
2019-06-11 17:03 ` Marc Zyngier
2019-06-11 17:03 ` [PATCH v2 1/9] KVM: arm/arm64: vgic: Add LPI translation cache definition Marc Zyngier
2019-06-11 17:03 ` Marc Zyngier
2019-06-11 17:03 ` Marc Zyngier
2019-06-12 8:16 ` Julien Thierry
2019-06-12 8:16 ` Julien Thierry
2019-06-12 8:16 ` Julien Thierry
2019-06-12 8:49 ` Julien Thierry [this message]
2019-06-12 8:49 ` Julien Thierry
2019-06-12 8:49 ` Julien Thierry
2019-06-12 9:52 ` Marc Zyngier
2019-06-12 9:52 ` Marc Zyngier
2019-06-12 10:58 ` Julien Thierry
2019-06-12 10:58 ` Julien Thierry
2019-06-12 10:58 ` Julien Thierry
2019-06-12 12:28 ` Julien Thierry
2019-06-12 12:28 ` Julien Thierry
2019-06-12 12:28 ` Julien Thierry
2019-07-23 12:43 ` Auger Eric
2019-07-23 12:43 ` Auger Eric
2019-07-23 12:43 ` Auger Eric
2019-06-11 17:03 ` [PATCH v2 2/9] KVM: arm/arm64: vgic: Add __vgic_put_lpi_locked primitive Marc Zyngier
2019-06-11 17:03 ` Marc Zyngier
2019-06-11 17:03 ` Marc Zyngier
2019-06-11 17:03 ` [PATCH v2 3/9] KVM: arm/arm64: vgic-its: Add MSI-LPI translation cache invalidation Marc Zyngier
2019-06-11 17:03 ` Marc Zyngier
2019-06-11 17:03 ` Marc Zyngier
2019-07-23 12:39 ` Auger Eric
2019-07-23 12:39 ` Auger Eric
2019-07-23 12:39 ` Auger Eric
2019-06-11 17:03 ` [PATCH v2 4/9] KVM: arm/arm64: vgic-its: Invalidate MSI-LPI translation cache on specific commands Marc Zyngier
2019-06-11 17:03 ` Marc Zyngier
2019-06-11 17:03 ` Marc Zyngier
2019-07-01 12:38 ` Auger Eric
2019-07-01 12:38 ` Auger Eric
2019-07-01 12:38 ` Auger Eric
2019-07-22 10:54 ` Marc Zyngier
2019-07-22 10:54 ` Marc Zyngier
2019-07-22 10:54 ` Marc Zyngier
2019-07-23 12:25 ` Auger Eric
2019-07-23 12:25 ` Auger Eric
2019-07-23 12:25 ` Auger Eric
2019-07-23 12:43 ` Marc Zyngier
2019-07-23 12:43 ` Marc Zyngier
2019-07-23 12:43 ` Marc Zyngier
2019-07-23 12:47 ` Auger Eric
2019-07-23 12:47 ` Auger Eric
2019-07-23 12:47 ` Auger Eric
2019-07-23 12:50 ` Marc Zyngier
2019-07-23 12:50 ` Marc Zyngier
2019-07-23 12:50 ` Marc Zyngier
2019-06-11 17:03 ` [PATCH v2 5/9] KVM: arm/arm64: vgic-its: Invalidate MSI-LPI translation cache on disabling LPIs Marc Zyngier
2019-06-11 17:03 ` Marc Zyngier
2019-06-11 17:03 ` Marc Zyngier
2019-07-23 15:09 ` Auger Eric
2019-07-23 15:09 ` Auger Eric
2019-07-23 15:09 ` Auger Eric
2019-06-11 17:03 ` [PATCH v2 6/9] KVM: arm/arm64: vgic-its: Invalidate MSI-LPI translation cache on vgic teardown Marc Zyngier
2019-06-11 17:03 ` Marc Zyngier
2019-06-11 17:03 ` Marc Zyngier
2019-07-23 15:10 ` Auger Eric
2019-07-23 15:10 ` Auger Eric
2019-07-23 15:10 ` Auger Eric
2019-06-11 17:03 ` [PATCH v2 7/9] KVM: arm/arm64: vgic-its: Cache successful MSI->LPI translation Marc Zyngier
2019-06-11 17:03 ` Marc Zyngier
2019-06-11 17:03 ` Marc Zyngier
2019-06-25 11:50 ` Zenghui Yu
2019-06-25 11:50 ` Zenghui Yu
2019-06-25 11:50 ` Zenghui Yu
2019-06-25 12:31 ` Marc Zyngier
2019-06-25 12:31 ` Marc Zyngier
2019-06-25 12:31 ` Marc Zyngier
2019-06-25 16:00 ` Zenghui Yu
2019-06-25 16:00 ` Zenghui Yu
2019-06-25 16:00 ` Zenghui Yu
2019-06-26 3:54 ` Zenghui Yu
2019-06-26 3:54 ` Zenghui Yu
2019-06-26 3:54 ` Zenghui Yu
2019-06-26 7:55 ` Marc Zyngier
2019-06-26 7:55 ` Marc Zyngier
2019-07-23 15:21 ` Auger Eric
2019-07-23 15:21 ` Auger Eric
2019-07-23 15:21 ` Auger Eric
2019-06-11 17:03 ` [PATCH v2 8/9] KVM: arm/arm64: vgic-its: Check the LPI translation cache on MSI injection Marc Zyngier
2019-06-11 17:03 ` Marc Zyngier
2019-06-11 17:03 ` Marc Zyngier
2019-07-23 15:10 ` Auger Eric
2019-07-23 15:10 ` Auger Eric
2019-07-23 15:10 ` Auger Eric
2019-07-23 15:45 ` Marc Zyngier
2019-07-23 15:45 ` Marc Zyngier
2019-07-23 15:45 ` Marc Zyngier
2019-07-24 7:41 ` Auger Eric
2019-07-24 7:41 ` Auger Eric
2019-07-24 7:41 ` Auger Eric
2019-06-11 17:03 ` [PATCH v2 9/9] KVM: arm/arm64: vgic-irqfd: Implement kvm_arch_set_irq_inatomic Marc Zyngier
2019-06-11 17:03 ` Marc Zyngier
2019-06-11 17:03 ` Marc Zyngier
2019-07-23 15:14 ` Auger Eric
2019-07-23 15:14 ` Auger Eric
2019-07-23 15:14 ` Auger Eric
2019-07-25 8:24 ` Marc Zyngier
2019-07-25 8:24 ` Marc Zyngier
2019-07-25 8:24 ` Marc Zyngier
2019-07-23 11:14 ` [PATCH v2 0/9] KVM: arm/arm64: vgic: ITS translation cache Andre Przywara
2019-07-23 11:14 ` Andre Przywara
2019-07-23 11:14 ` Andre Przywara
2019-07-25 8:50 ` Marc Zyngier
2019-07-25 8:50 ` Marc Zyngier
2019-07-25 8:50 ` Marc Zyngier
2019-07-25 10:01 ` Andre Przywara
2019-07-25 10:01 ` Andre Przywara
2019-07-25 10:01 ` Andre Przywara
2019-07-25 15:37 ` Marc Zyngier
2019-07-25 15:37 ` Marc Zyngier
2019-07-25 15:37 ` Marc Zyngier
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