[PATCH v4] iommu/dma: Use NUMA aware memory allocations in __iommu_dma_alloc_pages()

[PATCH v4] iommu/dma: Use NUMA aware memory allocations in __iommu_dma_alloc_pages()

[John Garry]

From: Ganapatrao Kulkarni <ganapatrao.kulkarni@cavium.com>

Change function __iommu_dma_alloc_pages() to allocate pages for DMA from
respective device NUMA node. The ternary operator which would be for
alloc_pages_node() is tidied along with this.

The motivation for this change is to have a policy for page allocation
consistent with direct DMA mapping, which attempts to allocate pages local
to the device, as mentioned in [1].

In addition, for certain workloads it has been observed a marginal
performance improvement. The patch caused an observation of 0.9% average
throughput improvement for running tcrypt with HiSilicon crypto engine.

We also include a modification to use kvzalloc() for kzalloc()/vzalloc()
combination.

[1] https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1692998.html

Signed-off-by: Ganapatrao Kulkarni <ganapatrao.kulkarni@cavium.com>
[JPG: Added kvzalloc(), drop pages ** being device local, remove ternary operator, update message]
Signed-off-by: John Garry <john.garry@huawei.com>
---
Difference:
v1->v2:
- Add Ganapatrao's tag and change author

v2->v3:
- removed ternary operator
- stopped making pages ** allocation local to device

v3->v4:
- Update commit message to include motivation for patch, including
  headline performance improvement for test.

Some notes:
This patch was originally posted by Ganapatrao in [2].

However, after initial review, it was never reposted (due to lack of
cycles, I think). In addition, the functionality in its sibling patches
were merged through patches, as mentioned in [2]; this also refers to a
discussion on device local allocations vs CPU local allocations for DMA
pool, and which is better [1].

However, as mentioned in [1], dma_alloc_coherent() uses the locality
information from the device - as in direct DMA - so this patch is just
applying this same policy.

And from some testing, mentioned in commit message, shows marginal
improvement.

[2] https://lore.kernel.org/patchwork/patch/833004/
[3] https://lkml.org/lkml/2018/8/22/391

diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index d1b0475..4afb1a8 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -449,20 +449,17 @@ static void __iommu_dma_free_pages(struct page **pages, int count)
 	kvfree(pages);
 }
 
-static struct page **__iommu_dma_alloc_pages(unsigned int count,
-		unsigned long order_mask, gfp_t gfp)
+static struct page **__iommu_dma_alloc_pages(struct device *dev,
+		unsigned int count, unsigned long order_mask, gfp_t gfp)
 {
 	struct page **pages;
-	unsigned int i = 0, array_size = count * sizeof(*pages);
+	unsigned int i = 0, nid = dev_to_node(dev);
 
 	order_mask &= (2U << MAX_ORDER) - 1;
 	if (!order_mask)
 		return NULL;
 
-	if (array_size <= PAGE_SIZE)
-		pages = kzalloc(array_size, GFP_KERNEL);
-	else
-		pages = vzalloc(array_size);
+	pages = kvzalloc(count * sizeof(*pages), GFP_KERNEL);
 	if (!pages)
 		return NULL;
 
@@ -481,10 +478,12 @@ static struct page **__iommu_dma_alloc_pages(unsigned int count,
 		for (order_mask &= (2U << __fls(count)) - 1;
 		     order_mask; order_mask &= ~order_size) {
 			unsigned int order = __fls(order_mask);
+			gfp_t alloc_flags = gfp;
 
 			order_size = 1U << order;
-			page = alloc_pages((order_mask - order_size) ?
-					   gfp | __GFP_NORETRY : gfp, order);
+			if (order_mask > order_size)
+				alloc_flags |= __GFP_NORETRY;
+			page = alloc_pages_node(nid, alloc_flags, order);
 			if (!page)
 				continue;
 			if (!order)
@@ -569,7 +568,8 @@ struct page **iommu_dma_alloc(struct device *dev, size_t size, gfp_t gfp,
 		alloc_sizes = min_size;
 
 	count = PAGE_ALIGN(size) >> PAGE_SHIFT;
-	pages = __iommu_dma_alloc_pages(count, alloc_sizes >> PAGE_SHIFT, gfp);
+	pages = __iommu_dma_alloc_pages(dev, count, alloc_sizes >> PAGE_SHIFT,
+					gfp);
 	if (!pages)
 		return NULL;
 
-- 
1.9.1

Re: [PATCH v4] iommu/dma: Use NUMA aware memory allocations in __iommu_dma_alloc_pages()

[John Garry]

On 30/11/2018 11:14, John Garry wrote:
> From: Ganapatrao Kulkarni <ganapatrao.kulkarni@cavium.com>
>

Hi Joerg,

A friendly reminder. Can you please let me know your position on this patch?

Cheers,
John

> Change function __iommu_dma_alloc_pages() to allocate pages for DMA from
> respective device NUMA node. The ternary operator which would be for
> alloc_pages_node() is tidied along with this.
>
> The motivation for this change is to have a policy for page allocation
> consistent with direct DMA mapping, which attempts to allocate pages local
> to the device, as mentioned in [1].
>
> In addition, for certain workloads it has been observed a marginal
> performance improvement. The patch caused an observation of 0.9% average
> throughput improvement for running tcrypt with HiSilicon crypto engine.
>
> We also include a modification to use kvzalloc() for kzalloc()/vzalloc()
> combination.
>
> [1] https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1692998.html
>
> Signed-off-by: Ganapatrao Kulkarni <ganapatrao.kulkarni@cavium.com>
> [JPG: Added kvzalloc(), drop pages ** being device local, remove ternary operator, update message]
> Signed-off-by: John Garry <john.garry@huawei.com>
> ---
> Difference:
> v1->v2:
> - Add Ganapatrao's tag and change author
>
> v2->v3:
> - removed ternary operator
> - stopped making pages ** allocation local to device
>
> v3->v4:
> - Update commit message to include motivation for patch, including
>   headline performance improvement for test.
>
> Some notes:
> This patch was originally posted by Ganapatrao in [2].
>
> However, after initial review, it was never reposted (due to lack of
> cycles, I think). In addition, the functionality in its sibling patches
> were merged through patches, as mentioned in [2]; this also refers to a
> discussion on device local allocations vs CPU local allocations for DMA
> pool, and which is better [1].
>
> However, as mentioned in [1], dma_alloc_coherent() uses the locality
> information from the device - as in direct DMA - so this patch is just
> applying this same policy.
>
> And from some testing, mentioned in commit message, shows marginal
> improvement.
>
> [2] https://lore.kernel.org/patchwork/patch/833004/
> [3] https://lkml.org/lkml/2018/8/22/391
>
> diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
> index d1b0475..4afb1a8 100644
> --- a/drivers/iommu/dma-iommu.c
> +++ b/drivers/iommu/dma-iommu.c
> @@ -449,20 +449,17 @@ static void __iommu_dma_free_pages(struct page **pages, int count)
>  	kvfree(pages);
>  }
>
> -static struct page **__iommu_dma_alloc_pages(unsigned int count,
> -		unsigned long order_mask, gfp_t gfp)
> +static struct page **__iommu_dma_alloc_pages(struct device *dev,
> +		unsigned int count, unsigned long order_mask, gfp_t gfp)
>  {
>  	struct page **pages;
> -	unsigned int i = 0, array_size = count * sizeof(*pages);
> +	unsigned int i = 0, nid = dev_to_node(dev);
>
>  	order_mask &= (2U << MAX_ORDER) - 1;
>  	if (!order_mask)
>  		return NULL;
>
> -	if (array_size <= PAGE_SIZE)
> -		pages = kzalloc(array_size, GFP_KERNEL);
> -	else
> -		pages = vzalloc(array_size);
> +	pages = kvzalloc(count * sizeof(*pages), GFP_KERNEL);
>  	if (!pages)
>  		return NULL;
>
> @@ -481,10 +478,12 @@ static struct page **__iommu_dma_alloc_pages(unsigned int count,
>  		for (order_mask &= (2U << __fls(count)) - 1;
>  		     order_mask; order_mask &= ~order_size) {
>  			unsigned int order = __fls(order_mask);
> +			gfp_t alloc_flags = gfp;
>
>  			order_size = 1U << order;
> -			page = alloc_pages((order_mask - order_size) ?
> -					   gfp | __GFP_NORETRY : gfp, order);
> +			if (order_mask > order_size)
> +				alloc_flags |= __GFP_NORETRY;
> +			page = alloc_pages_node(nid, alloc_flags, order);
>  			if (!page)
>  				continue;
>  			if (!order)
> @@ -569,7 +568,8 @@ struct page **iommu_dma_alloc(struct device *dev, size_t size, gfp_t gfp,
>  		alloc_sizes = min_size;
>
>  	count = PAGE_ALIGN(size) >> PAGE_SHIFT;
> -	pages = __iommu_dma_alloc_pages(count, alloc_sizes >> PAGE_SHIFT, gfp);
> +	pages = __iommu_dma_alloc_pages(dev, count, alloc_sizes >> PAGE_SHIFT,
> +					gfp);
>  	if (!pages)
>  		return NULL;
>
>

Re: [PATCH v4] iommu/dma: Use NUMA aware memory allocations in __iommu_dma_alloc_pages()

[Joerg Roedel]

On Fri, Dec 07, 2018 at 05:57:42PM +0000, John Garry wrote:
> A friendly reminder. Can you please let me know your position on this patch?

I am waiting for a Reviewed-by or at least Acked-by from Robin on it
before I put it in my tree.


Regards,

	Joerg

Re: [PATCH v4] iommu/dma: Use NUMA aware memory allocations in __iommu_dma_alloc_pages()

[Robin Murphy]

On 30/11/2018 11:14, John Garry wrote:
> From: Ganapatrao Kulkarni <ganapatrao.kulkarni@cavium.com>
> 
> Change function __iommu_dma_alloc_pages() to allocate pages for DMA from
> respective device NUMA node. The ternary operator which would be for
> alloc_pages_node() is tidied along with this.
> 
> The motivation for this change is to have a policy for page allocation
> consistent with direct DMA mapping, which attempts to allocate pages local
> to the device, as mentioned in [1].
> 
> In addition, for certain workloads it has been observed a marginal
> performance improvement. The patch caused an observation of 0.9% average
> throughput improvement for running tcrypt with HiSilicon crypto engine.
> 
> We also include a modification to use kvzalloc() for kzalloc()/vzalloc()
> combination.
> 
> [1] https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1692998.html

Reviewed-by: Robin Murphy <robin.murphy@arm.com>

> Signed-off-by: Ganapatrao Kulkarni <ganapatrao.kulkarni@cavium.com>
> [JPG: Added kvzalloc(), drop pages ** being device local, remove ternary operator, update message]
> Signed-off-by: John Garry <john.garry@huawei.com>
> ---
> Difference:
> v1->v2:
> - Add Ganapatrao's tag and change author
> 
> v2->v3:
> - removed ternary operator
> - stopped making pages ** allocation local to device
> 
> v3->v4:
> - Update commit message to include motivation for patch, including
>    headline performance improvement for test.
> 
> Some notes:
> This patch was originally posted by Ganapatrao in [2].
> 
> However, after initial review, it was never reposted (due to lack of
> cycles, I think). In addition, the functionality in its sibling patches
> were merged through patches, as mentioned in [2]; this also refers to a
> discussion on device local allocations vs CPU local allocations for DMA
> pool, and which is better [1].
> 
> However, as mentioned in [1], dma_alloc_coherent() uses the locality
> information from the device - as in direct DMA - so this patch is just
> applying this same policy.
> 
> And from some testing, mentioned in commit message, shows marginal
> improvement.
> 
> [2] https://lore.kernel.org/patchwork/patch/833004/
> [3] https://lkml.org/lkml/2018/8/22/391
> 
> diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
> index d1b0475..4afb1a8 100644
> --- a/drivers/iommu/dma-iommu.c
> +++ b/drivers/iommu/dma-iommu.c
> @@ -449,20 +449,17 @@ static void __iommu_dma_free_pages(struct page **pages, int count)
>   	kvfree(pages);
>   }
>   
> -static struct page **__iommu_dma_alloc_pages(unsigned int count,
> -		unsigned long order_mask, gfp_t gfp)
> +static struct page **__iommu_dma_alloc_pages(struct device *dev,
> +		unsigned int count, unsigned long order_mask, gfp_t gfp)
>   {
>   	struct page **pages;
> -	unsigned int i = 0, array_size = count * sizeof(*pages);
> +	unsigned int i = 0, nid = dev_to_node(dev);
>   
>   	order_mask &= (2U << MAX_ORDER) - 1;
>   	if (!order_mask)
>   		return NULL;
>   
> -	if (array_size <= PAGE_SIZE)
> -		pages = kzalloc(array_size, GFP_KERNEL);
> -	else
> -		pages = vzalloc(array_size);
> +	pages = kvzalloc(count * sizeof(*pages), GFP_KERNEL);
>   	if (!pages)
>   		return NULL;
>   
> @@ -481,10 +478,12 @@ static struct page **__iommu_dma_alloc_pages(unsigned int count,
>   		for (order_mask &= (2U << __fls(count)) - 1;
>   		     order_mask; order_mask &= ~order_size) {
>   			unsigned int order = __fls(order_mask);
> +			gfp_t alloc_flags = gfp;
>   
>   			order_size = 1U << order;
> -			page = alloc_pages((order_mask - order_size) ?
> -					   gfp | __GFP_NORETRY : gfp, order);
> +			if (order_mask > order_size)
> +				alloc_flags |= __GFP_NORETRY;
> +			page = alloc_pages_node(nid, alloc_flags, order);
>   			if (!page)
>   				continue;
>   			if (!order)
> @@ -569,7 +568,8 @@ struct page **iommu_dma_alloc(struct device *dev, size_t size, gfp_t gfp,
>   		alloc_sizes = min_size;
>   
>   	count = PAGE_ALIGN(size) >> PAGE_SHIFT;
> -	pages = __iommu_dma_alloc_pages(count, alloc_sizes >> PAGE_SHIFT, gfp);
> +	pages = __iommu_dma_alloc_pages(dev, count, alloc_sizes >> PAGE_SHIFT,
> +					gfp);
>   	if (!pages)
>   		return NULL;
>   
> 

Re: [PATCH v4] iommu/dma: Use NUMA aware memory allocations in __iommu_dma_alloc_pages()

[Joerg Roedel]

On Fri, Nov 30, 2018 at 07:14:00PM +0800, John Garry wrote:
> From: Ganapatrao Kulkarni <ganapatrao.kulkarni@cavium.com>
> 
> Change function __iommu_dma_alloc_pages() to allocate pages for DMA from
> respective device NUMA node. The ternary operator which would be for
> alloc_pages_node() is tidied along with this.
> 
> The motivation for this change is to have a policy for page allocation
> consistent with direct DMA mapping, which attempts to allocate pages local
> to the device, as mentioned in [1].
> 
> In addition, for certain workloads it has been observed a marginal
> performance improvement. The patch caused an observation of 0.9% average
> throughput improvement for running tcrypt with HiSilicon crypto engine.
> 
> We also include a modification to use kvzalloc() for kzalloc()/vzalloc()
> combination.
> 
> [1] https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1692998.html
> 
> Signed-off-by: Ganapatrao Kulkarni <ganapatrao.kulkarni@cavium.com>
> [JPG: Added kvzalloc(), drop pages ** being device local, remove ternary operator, update message]
> Signed-off-by: John Garry <john.garry@huawei.com>

Applied, thanks.