iommu/dma: Use NUMA aware memory allocations in __iommu_dma_alloc_pages() (c4b17afb) · Commits · 戴 / test

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> Reviewed-by:

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

Joerg Roedel <jroedel@suse.de>

drivers/iommu/dma-iommu.c

+10 −10

Original line number	Diff line number	Diff line
		@@ -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;

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