* [Qemu-devel] [PATCH] kvm: do not flush after deleting gsi
@ 2012-12-12 10:48 Michael S. Tsirkin
2012-12-12 11:39 ` Jan Kiszka
2012-12-13 4:55 ` Asias He
0 siblings, 2 replies; 5+ messages in thread
From: Michael S. Tsirkin @ 2012-12-12 10:48 UTC (permalink / raw)
To: qemu-devel, asias
Cc: Peter Maydell, kvm, Michael S. Tsirkin, Jan Kiszka,
Marcelo Tosatti, Avi Kivity
Deleting a GSI isn't necessary: it is enough
to stop using it. Delay flush until an entry is used.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
kvm-all.c | 2 --
1 file changed, 2 deletions(-)
diff --git a/kvm-all.c b/kvm-all.c
index 3bc3347..fb3180d 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -991,8 +991,6 @@ void kvm_irqchip_release_virq(KVMState *s, int virq)
}
}
clear_gsi(s, virq);
-
- kvm_irqchip_commit_routes(s);
}
static unsigned int kvm_hash_msi(uint32_t data)
--
MST
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [Qemu-devel] [PATCH] kvm: do not flush after deleting gsi
2012-12-12 10:48 [Qemu-devel] [PATCH] kvm: do not flush after deleting gsi Michael S. Tsirkin
@ 2012-12-12 11:39 ` Jan Kiszka
2012-12-13 4:55 ` Asias He
1 sibling, 0 replies; 5+ messages in thread
From: Jan Kiszka @ 2012-12-12 11:39 UTC (permalink / raw)
To: Michael S. Tsirkin
Cc: Peter Maydell, kvm@vger.kernel.org, Marcelo Tosatti,
qemu-devel@nongnu.org, Avi Kivity, asias@redhat.com
On 2012-12-12 11:48, Michael S. Tsirkin wrote:
> Deleting a GSI isn't necessary: it is enough
> to stop using it. Delay flush until an entry is used.
>
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> ---
> kvm-all.c | 2 --
> 1 file changed, 2 deletions(-)
>
> diff --git a/kvm-all.c b/kvm-all.c
> index 3bc3347..fb3180d 100644
> --- a/kvm-all.c
> +++ b/kvm-all.c
> @@ -991,8 +991,6 @@ void kvm_irqchip_release_virq(KVMState *s, int virq)
> }
> }
> clear_gsi(s, virq);
> -
> - kvm_irqchip_commit_routes(s);
> }
>
> static unsigned int kvm_hash_msi(uint32_t data)
>
Reviewed-by: Jan Kiszka <jan.kiszka@siemens.com>
--
Siemens AG, Corporate Technology, CT RTC ITP SDP-DE
Corporate Competence Center Embedded Linux
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [Qemu-devel] [PATCH] kvm: do not flush after deleting gsi
2012-12-12 10:48 [Qemu-devel] [PATCH] kvm: do not flush after deleting gsi Michael S. Tsirkin
2012-12-12 11:39 ` Jan Kiszka
@ 2012-12-13 4:55 ` Asias He
2012-12-13 15:34 ` Jan Kiszka
1 sibling, 1 reply; 5+ messages in thread
From: Asias He @ 2012-12-13 4:55 UTC (permalink / raw)
To: Michael S. Tsirkin
Cc: Jan Kiszka, Marcelo Tosatti, qemu-devel, kvm, Peter Maydell
Hello Michael,
On 12/12/2012 06:48 PM, Michael S. Tsirkin wrote:
> Deleting a GSI isn't necessary: it is enough
> to stop using it. Delay flush until an entry is used.
>
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> ---
> kvm-all.c | 2 --
> 1 file changed, 2 deletions(-)
>
> diff --git a/kvm-all.c b/kvm-all.c
> index 3bc3347..fb3180d 100644
> --- a/kvm-all.c
> +++ b/kvm-all.c
> @@ -991,8 +991,6 @@ void kvm_irqchip_release_virq(KVMState *s, int virq)
> }
> }
> clear_gsi(s, virq);
> -
> - kvm_irqchip_commit_routes(s);
> }
>
> static unsigned int kvm_hash_msi(uint32_t data)
>
I tried this patch with vhost-blk with qemu-1.3.0
6d6c9f59ca1b1a76ade7ad868bef191818f58819.
Without the drop of msix_fire_vector_notifier in msix_handle_mask_update
hack
Before: ~20K IOPS
After: ~35K IOPS
With the drop of msix_fire_vector_notifier in
msix_handle_mask_update hack
Before: ~197K IOPS
After: ~197K IOPS
--
Asias
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [Qemu-devel] [PATCH] kvm: do not flush after deleting gsi
2012-12-13 4:55 ` Asias He
@ 2012-12-13 15:34 ` Jan Kiszka
2012-12-14 1:00 ` Asias He
0 siblings, 1 reply; 5+ messages in thread
From: Jan Kiszka @ 2012-12-13 15:34 UTC (permalink / raw)
To: Asias He
Cc: Peter Maydell, Marcelo Tosatti, qemu-devel@nongnu.org,
kvm@vger.kernel.org, Michael S. Tsirkin
On 2012-12-13 05:55, Asias He wrote:
> Hello Michael,
>
> On 12/12/2012 06:48 PM, Michael S. Tsirkin wrote:
>> Deleting a GSI isn't necessary: it is enough
>> to stop using it. Delay flush until an entry is used.
>>
>> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
>> ---
>> kvm-all.c | 2 --
>> 1 file changed, 2 deletions(-)
>>
>> diff --git a/kvm-all.c b/kvm-all.c
>> index 3bc3347..fb3180d 100644
>> --- a/kvm-all.c
>> +++ b/kvm-all.c
>> @@ -991,8 +991,6 @@ void kvm_irqchip_release_virq(KVMState *s, int virq)
>> }
>> }
>> clear_gsi(s, virq);
>> -
>> - kvm_irqchip_commit_routes(s);
>> }
>>
>> static unsigned int kvm_hash_msi(uint32_t data)
>>
>
> I tried this patch with vhost-blk with qemu-1.3.0
> 6d6c9f59ca1b1a76ade7ad868bef191818f58819.
>
> Without the drop of msix_fire_vector_notifier in msix_handle_mask_update
> hack
> Before: ~20K IOPS
> After: ~35K IOPS
>
> With the drop of msix_fire_vector_notifier in
> msix_handle_mask_update hack
> Before: ~197K IOPS
> After: ~197K IOPS
>
Is the guest balancing the IRQ(s) between its vCPUs all the time?
Jan
--
Siemens AG, Corporate Technology, CT RTC ITP SDP-DE
Corporate Competence Center Embedded Linux
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [Qemu-devel] [PATCH] kvm: do not flush after deleting gsi
2012-12-13 15:34 ` Jan Kiszka
@ 2012-12-14 1:00 ` Asias He
0 siblings, 0 replies; 5+ messages in thread
From: Asias He @ 2012-12-14 1:00 UTC (permalink / raw)
To: Jan Kiszka
Cc: Peter Maydell, Marcelo Tosatti, qemu-devel@nongnu.org,
kvm@vger.kernel.org, Michael S. Tsirkin
Hello Jan,
On 12/13/2012 11:34 PM, Jan Kiszka wrote:
> On 2012-12-13 05:55, Asias He wrote:
>> Hello Michael,
>>
>> On 12/12/2012 06:48 PM, Michael S. Tsirkin wrote:
>>> Deleting a GSI isn't necessary: it is enough
>>> to stop using it. Delay flush until an entry is used.
>>>
>>> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
>>> ---
>>> kvm-all.c | 2 --
>>> 1 file changed, 2 deletions(-)
>>>
>>> diff --git a/kvm-all.c b/kvm-all.c
>>> index 3bc3347..fb3180d 100644
>>> --- a/kvm-all.c
>>> +++ b/kvm-all.c
>>> @@ -991,8 +991,6 @@ void kvm_irqchip_release_virq(KVMState *s, int virq)
>>> }
>>> }
>>> clear_gsi(s, virq);
>>> -
>>> - kvm_irqchip_commit_routes(s);
>>> }
>>>
>>> static unsigned int kvm_hash_msi(uint32_t data)
>>>
>>
>> I tried this patch with vhost-blk with qemu-1.3.0
>> 6d6c9f59ca1b1a76ade7ad868bef191818f58819.
>>
>> Without the drop of msix_fire_vector_notifier in msix_handle_mask_update
>> hack
>> Before: ~20K IOPS
>> After: ~35K IOPS
>>
>> With the drop of msix_fire_vector_notifier in
>> msix_handle_mask_update hack
>> Before: ~197K IOPS
>> After: ~197K IOPS
>>
>
> Is the guest balancing the IRQ(s) between its vCPUs all the time?
Yes. In all of the four the cases (w/o gsi patch, w/o drop of
msix_fire_vector_notifier hack), IRQs balanced evenly in all vCPUs.
--
Asias
^ permalink raw reply [flat|nested] 5+ messages in thread
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2012-12-12 10:48 [Qemu-devel] [PATCH] kvm: do not flush after deleting gsi Michael S. Tsirkin
2012-12-12 11:39 ` Jan Kiszka
2012-12-13 4:55 ` Asias He
2012-12-13 15:34 ` Jan Kiszka
2012-12-14 1:00 ` Asias He
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