[PATCH] iommu/vt-d: add NUMA awareness to intel_alloc_coherent()

From: Eric Dumazet
Date: Wed Jan 31 2018 - 17:46:05 EST


From: Eric Dumazet <edumazet@xxxxxxxxxx>

Some devices (like mlx4) try hard to allocate memory on selected
NUMA node, but it turns out intel_alloc_coherent() is not NUMA
aware yet.

Note that dma_generic_alloc_coherent() in arch/x86/kernel/pci-dma.c
gets this right.

Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Cc: Benjamin Serebrin <serebrin@xxxxxxxxxx>
Cc: David Woodhouse <dwmw2@xxxxxxxxxxxxx>
Cc: Joerg Roedel <joro@xxxxxxxxxx>
---
Âdrivers/iommu/intel-iommu.c |ÂÂÂÂ7 +++++--
Â1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index a1373cf343269455808f66ad18dc0a2fb7aa73f2..0efef077abc099eb29ebc5cefdd1b996f025dffd 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -3734,8 +3734,11 @@ static void *intel_alloc_coherent(struct device *dev, size_t size,
}
}

- if (!page)
- page = alloc_pages(flags, order);
+ if (!page) {
+ page = alloc_pages_node(dev_to_node(dev), flags, order);
+ if (!page)
+ page = alloc_pages(flags, order);
+ }
if (!page)
return NULL;
memset(page_address(page), 0, size);