diff mbox series

[v4,2/2] arm64: mm: reserve per-numa CMA to localize coherent dma buffers

Message ID 20200723131344.41472-3-song.bao.hua@hisilicon.com (mailing list archive)
State New, archived
Headers show
Series make dma_alloc_coherent NUMA-aware by per-NUMA CMA | expand

Commit Message

Song Bao Hua (Barry Song) July 23, 2020, 1:13 p.m. UTC 
Right now, smmu is using dma_alloc_coherent() to get memory to save queues
and tables. Typically, on ARM64 server, there is a default CMA located at
node0, which could be far away from node2, node3 etc.
with this patch, smmu will get memory from local numa node to save command
queues and page tables. that means dma_unmap latency will be shrunk much.
Meanwhile, when iommu.passthrough is on, device drivers which call dma_
alloc_coherent() will also get local memory and avoid the travel between
numa nodes.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Will Deacon <will@kernel.org>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Ganapatrao Kulkarni <ganapatrao.kulkarni@cavium.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Cc: Steve Capper <steve.capper@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Barry Song <song.bao.hua@hisilicon.com>
---
 -v4:
 * rebase on top of linux-next to avoid arch/arm64 conflicts

 arch/arm64/mm/init.c | 2 ++
 1 file changed, 2 insertions(+)

Comments

Christoph Hellwig July 28, 2020, 11:53 a.m. UTC | #1 
Looks ok to me, but before I pick the series up in the dma-mapping tree
I really want an ACK from the arm64 maintainers.
diff mbox series

Patch

diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index b6881d61b818..a6e19145ebb3 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -437,6 +437,8 @@  void __init bootmem_init(void)
 	arm64_hugetlb_cma_reserve();
 #endif
 
+	dma_pernuma_cma_reserve();
+
 	memblock_dump_all();
 }