Displaying 2 results from an estimated 2 matches for "virt_to_phys_hard".
Did you mean:
virt_to_phys_harder
2012 Oct 18
1
[PATCH] virtio: 9p: correctly pass physical address to userspace for high pages
...esc[head].flags = VRING_DESC_F_INDIRECT;
> - vq->vring.desc[head].addr = virt_to_phys(desc);
> + vq->vring.desc[head].addr = page_to_phys(kmap_to_page(desc)) +
> + ((unsigned long)desc & ~PAGE_MASK);
> vq->vring.desc[head].len = i * sizeof(struct vring_desc);
Gah, virt_to_phys_harder()?
What's the performance effect? If it's negligible, why doesn't
virt_to_phys() just do this for us?
We do have an alternate solution: masking out __GFP_HIGHMEM from the
kmalloc of desc. If it fails, we will fall back to laying out the
virtio request directly inside the ring; if...
2012 Oct 18
1
[PATCH] virtio: 9p: correctly pass physical address to userspace for high pages
...esc[head].flags = VRING_DESC_F_INDIRECT;
> - vq->vring.desc[head].addr = virt_to_phys(desc);
> + vq->vring.desc[head].addr = page_to_phys(kmap_to_page(desc)) +
> + ((unsigned long)desc & ~PAGE_MASK);
> vq->vring.desc[head].len = i * sizeof(struct vring_desc);
Gah, virt_to_phys_harder()?
What's the performance effect? If it's negligible, why doesn't
virt_to_phys() just do this for us?
We do have an alternate solution: masking out __GFP_HIGHMEM from the
kmalloc of desc. If it fails, we will fall back to laying out the
virtio request directly inside the ring; if...