[PATCH 35/94] xen/privcmd: Optimized privcmd_ioctl_mmap() by using vma_lookup()

Liam Howlett liam.howlett at oracle.com
Wed Apr 28 16:36:06 BST 2021


vma_lookup() walks the VMA tree for a specific value, find_vma() will
search the tree after walking to a specific value.  It is more efficient
to only walk to the requested value as this case requires the address to
equal the vm_start.

Signed-off-by: Liam R. Howlett <Liam.Howlett at Oracle.com>
---
 drivers/xen/privcmd.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/xen/privcmd.c b/drivers/xen/privcmd.c
index 720a7b7abd46..5f903ae9af7e 100644
--- a/drivers/xen/privcmd.c
+++ b/drivers/xen/privcmd.c
@@ -282,7 +282,7 @@ static long privcmd_ioctl_mmap(struct file *file, void __user *udata)
 						     struct page, lru);
 		struct privcmd_mmap_entry *msg = page_address(page);
 
-		vma = find_vma(mm, msg->va);
+		vma = vma_lookup(mm, msg->va);
 		rc = -EINVAL;
 
 		if (!vma || (msg->va != vma->vm_start) || vma->vm_private_data)
-- 
2.30.2



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