Re: [PATCH v2] virtio_ring: use alloc_pages_node for NUMA-aware allocation
From: "Michael S. Tsirkin" <mst@redhat.com>
Date: 2020-07-21 08:19:15
Also in:
linux-pci, lkml
On Tue, Jul 21, 2020 at 03:00:13PM +0800, Shile Zhang wrote:
Use alloc_pages_node() allocate memory for vring queue with proper NUMA affinity. Reported-by: kernel test robot <redacted> Suggested-by: Jiang Liu <redacted> Signed-off-by: Shile Zhang <redacted>
Do you observe any performance gains from this patch? I also wonder why isn't the probe code run on the correct numa node? That would fix a wide class of issues like this without need to tweak drivers. Bjorn, what do you think? Was this considered?
quoted hunk ↗ jump to hunk
--- Changelog v1 -> v2: - fixed compile warning reported by LKP. --- drivers/virtio/virtio_ring.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-)diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c index 58b96baa8d48..d38fd6872c8c 100644 --- a/drivers/virtio/virtio_ring.c +++ b/drivers/virtio/virtio_ring.c@@ -276,9 +276,11 @@ static void *vring_alloc_queue(struct virtio_device *vdev, size_t size, return dma_alloc_coherent(vdev->dev.parent, size, dma_handle, flag); } else { - void *queue = alloc_pages_exact(PAGE_ALIGN(size), flag); - - if (queue) { + void *queue = NULL; + struct page *page = alloc_pages_node(dev_to_node(vdev->dev.parent), + flag, get_order(size)); + if (page) { + queue = page_address(page); phys_addr_t phys_addr = virt_to_phys(queue); *dma_handle = (dma_addr_t)phys_addr;@@ -308,7 +310,7 @@ static void vring_free_queue(struct virtio_device *vdev, size_t size, if (vring_use_dma_api(vdev)) dma_free_coherent(vdev->dev.parent, size, queue, dma_handle); else - free_pages_exact(queue, PAGE_ALIGN(size)); + free_pages((unsigned long)queue, get_order(size)); } /*-- 2.24.0.rc2