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* [PATCH v2] virtio_ring: use alloc_pages_node for NUMA-aware allocation
@ 2020-07-21  7:00 Shile Zhang
  2020-07-21  8:18 ` Michael S. Tsirkin
  0 siblings, 1 reply; 3+ messages in thread
From: Shile Zhang @ 2020-07-21  7:00 UTC (permalink / raw)
  To: Michael S . Tsirkin, Jason Wang
  Cc: virtualization, linux-kernel, Shile Zhang, kernel test robot, Jiang Liu

Use alloc_pages_node() allocate memory for vring queue with proper
NUMA affinity.

Reported-by: kernel test robot <lkp@intel.com>
Suggested-by: Jiang Liu <liuj97@gmail.com>
Signed-off-by: Shile Zhang <shile.zhang@linux.alibaba.com>
---
Changelog
v1 -> v2:
- fixed compile warning reported by LKP.
---
 drivers/virtio/virtio_ring.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 58b96baa8d48..d38fd6872c8c 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -276,9 +276,11 @@ static void *vring_alloc_queue(struct virtio_device *vdev, size_t size,
 		return dma_alloc_coherent(vdev->dev.parent, size,
 					  dma_handle, flag);
 	} else {
-		void *queue = alloc_pages_exact(PAGE_ALIGN(size), flag);
-
-		if (queue) {
+		void *queue = NULL;
+		struct page *page = alloc_pages_node(dev_to_node(vdev->dev.parent),
+						     flag, get_order(size));
+		if (page) {
+			queue = page_address(page);
 			phys_addr_t phys_addr = virt_to_phys(queue);
 			*dma_handle = (dma_addr_t)phys_addr;
 
@@ -308,7 +310,7 @@ static void vring_free_queue(struct virtio_device *vdev, size_t size,
 	if (vring_use_dma_api(vdev))
 		dma_free_coherent(vdev->dev.parent, size, queue, dma_handle);
 	else
-		free_pages_exact(queue, PAGE_ALIGN(size));
+		free_pages((unsigned long)queue, get_order(size));
 }
 
 /*
-- 
2.24.0.rc2

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH v2] virtio_ring: use alloc_pages_node for NUMA-aware allocation
  2020-07-21  7:00 [PATCH v2] virtio_ring: use alloc_pages_node for NUMA-aware allocation Shile Zhang
@ 2020-07-21  8:18 ` Michael S. Tsirkin
  2020-07-21 11:28   ` Shile Zhang
  0 siblings, 1 reply; 3+ messages in thread
From: Michael S. Tsirkin @ 2020-07-21  8:18 UTC (permalink / raw)
  To: Shile Zhang
  Cc: Jason Wang, virtualization, linux-kernel, kernel test robot,
	Jiang Liu, linux-pci, bhelgaas

On Tue, Jul 21, 2020 at 03:00:13PM +0800, Shile Zhang wrote:
> Use alloc_pages_node() allocate memory for vring queue with proper
> NUMA affinity.
> 
> Reported-by: kernel test robot <lkp@intel.com>
> Suggested-by: Jiang Liu <liuj97@gmail.com>
> Signed-off-by: Shile Zhang <shile.zhang@linux.alibaba.com>

Do you observe any performance gains from this patch?

I also wonder why isn't the probe code run on the correct numa node?
That would fix a wide class of issues like this without need to tweak
drivers.

Bjorn, what do you think? Was this considered?

> ---
> Changelog
> v1 -> v2:
> - fixed compile warning reported by LKP.
> ---
>  drivers/virtio/virtio_ring.c | 10 ++++++----
>  1 file changed, 6 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
> index 58b96baa8d48..d38fd6872c8c 100644
> --- a/drivers/virtio/virtio_ring.c
> +++ b/drivers/virtio/virtio_ring.c
> @@ -276,9 +276,11 @@ static void *vring_alloc_queue(struct virtio_device *vdev, size_t size,
>  		return dma_alloc_coherent(vdev->dev.parent, size,
>  					  dma_handle, flag);
>  	} else {
> -		void *queue = alloc_pages_exact(PAGE_ALIGN(size), flag);
> -
> -		if (queue) {
> +		void *queue = NULL;
> +		struct page *page = alloc_pages_node(dev_to_node(vdev->dev.parent),
> +						     flag, get_order(size));
> +		if (page) {
> +			queue = page_address(page);
>  			phys_addr_t phys_addr = virt_to_phys(queue);
>  			*dma_handle = (dma_addr_t)phys_addr;
>  
> @@ -308,7 +310,7 @@ static void vring_free_queue(struct virtio_device *vdev, size_t size,
>  	if (vring_use_dma_api(vdev))
>  		dma_free_coherent(vdev->dev.parent, size, queue, dma_handle);
>  	else
> -		free_pages_exact(queue, PAGE_ALIGN(size));
> +		free_pages((unsigned long)queue, get_order(size));
>  }
>  
>  /*
> -- 
> 2.24.0.rc2

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: [PATCH v2] virtio_ring: use alloc_pages_node for NUMA-aware allocation
  2020-07-21  8:18 ` Michael S. Tsirkin
@ 2020-07-21 11:28   ` Shile Zhang
  0 siblings, 0 replies; 3+ messages in thread
From: Shile Zhang @ 2020-07-21 11:28 UTC (permalink / raw)
  To: Michael S. Tsirkin
  Cc: Jason Wang, virtualization, linux-kernel, kernel test robot,
	Jiang Liu, linux-pci, bhelgaas



On 2020/7/21 16:18, Michael S. Tsirkin wrote:
> On Tue, Jul 21, 2020 at 03:00:13PM +0800, Shile Zhang wrote:
>> Use alloc_pages_node() allocate memory for vring queue with proper
>> NUMA affinity.
>>
>> Reported-by: kernel test robot <lkp@intel.com>
>> Suggested-by: Jiang Liu <liuj97@gmail.com>
>> Signed-off-by: Shile Zhang <shile.zhang@linux.alibaba.com>
> 
> Do you observe any performance gains from this patch?

Thanks for your comments!
Yes, the bandwidth can boost more than doubled (from 30Gbps to 80GBps) 
with this changes in my test env (8 numa nodes), with netperf test.

> 
> I also wonder why isn't the probe code run on the correct numa node?
> That would fix a wide class of issues like this without need to tweak
> drivers.

Good point, I'll check this, thanks!

> 
> Bjorn, what do you think? Was this considered?
> 
>> ---
>> Changelog
>> v1 -> v2:
>> - fixed compile warning reported by LKP.
>> ---
>>   drivers/virtio/virtio_ring.c | 10 ++++++----
>>   1 file changed, 6 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
>> index 58b96baa8d48..d38fd6872c8c 100644
>> --- a/drivers/virtio/virtio_ring.c
>> +++ b/drivers/virtio/virtio_ring.c
>> @@ -276,9 +276,11 @@ static void *vring_alloc_queue(struct virtio_device *vdev, size_t size,
>>   		return dma_alloc_coherent(vdev->dev.parent, size,
>>   					  dma_handle, flag);
>>   	} else {
>> -		void *queue = alloc_pages_exact(PAGE_ALIGN(size), flag);
>> -
>> -		if (queue) {
>> +		void *queue = NULL;
>> +		struct page *page = alloc_pages_node(dev_to_node(vdev->dev.parent),
>> +						     flag, get_order(size));
>> +		if (page) {
>> +			queue = page_address(page);
>>   			phys_addr_t phys_addr = virt_to_phys(queue);
>>   			*dma_handle = (dma_addr_t)phys_addr;
>>   
>> @@ -308,7 +310,7 @@ static void vring_free_queue(struct virtio_device *vdev, size_t size,
>>   	if (vring_use_dma_api(vdev))
>>   		dma_free_coherent(vdev->dev.parent, size, queue, dma_handle);
>>   	else
>> -		free_pages_exact(queue, PAGE_ALIGN(size));
>> +		free_pages((unsigned long)queue, get_order(size));
>>   }
>>   
>>   /*
>> -- 
>> 2.24.0.rc2

^ permalink raw reply	[flat|nested] 3+ messages in thread

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Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2020-07-21  7:00 [PATCH v2] virtio_ring: use alloc_pages_node for NUMA-aware allocation Shile Zhang
2020-07-21  8:18 ` Michael S. Tsirkin
2020-07-21 11:28   ` Shile Zhang

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