Re: [PATCH 4/4] iommu/dma, numa: Use NUMA aware memory allocations in __iommu_dma_alloc_pages

From: Robin Murphy
Date: Thu Sep 21 2017 - 07:41:21 EST


On 21/09/17 09:59, Ganapatrao Kulkarni wrote:
> Change function __iommu_dma_alloc_pages to allocate memory/pages
> for dma from respective device numa node.
>
> Signed-off-by: Ganapatrao Kulkarni <ganapatrao.kulkarni@xxxxxxxxxx>
> ---
> drivers/iommu/dma-iommu.c | 17 ++++++++++-------
> 1 file changed, 10 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
> index 9d1cebe..0626b58 100644
> --- a/drivers/iommu/dma-iommu.c
> +++ b/drivers/iommu/dma-iommu.c
> @@ -428,20 +428,21 @@ 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);
> + int numa_node = 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);
> + pages = kzalloc_node(array_size, GFP_KERNEL, numa_node);
> else
> - pages = vzalloc(array_size);
> + pages = vzalloc_node(array_size, numa_node);

kvzalloc{,_node}() didn't exist when this code was first written, but it
does now - since you're touching it you may as well get rid of the whole
if-else and array_size local.

Further nit: some of the indentation below is a bit messed up.

Robin.

> if (!pages)
> return NULL;
>
> @@ -462,8 +463,9 @@ static struct page **__iommu_dma_alloc_pages(unsigned int count,
> unsigned int order = __fls(order_mask);
>
> order_size = 1U << order;
> - page = alloc_pages((order_mask - order_size) ?
> - gfp | __GFP_NORETRY : gfp, order);
> + page = alloc_pages_node(numa_node,
> + (order_mask - order_size) ?
> + gfp | __GFP_NORETRY : gfp, order);
> if (!page)
> continue;
> if (!order)
> @@ -548,7 +550,8 @@ 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;
>
>