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From:   Liam Howlett <liam.howlett@oracle.com>
To:     "maple-tree@lists.infradead.org" <maple-tree@lists.infradead.org>,
        "linux-mm@kvack.org" <linux-mm@kvack.org>,
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        Michel Lespinasse <walken.cr@gmail.com>,
        Liam Howlett <liam.howlett@oracle.com>
Subject: [PATCH 35/94] xen/privcmd: Optimized privcmd_ioctl_mmap() by using
 vma_lookup()
Thread-Topic: [PATCH 35/94] xen/privcmd: Optimized privcmd_ioctl_mmap() by
 using vma_lookup()
Thread-Index: AQHXPEQ0lFso/sjA+0CVe97NQiFWlQ==
Date:   Wed, 28 Apr 2021 15:36:06 +0000
Message-ID: <20210428153542.2814175-36-Liam.Howlett@Oracle.com>
References: <20210428153542.2814175-1-Liam.Howlett@Oracle.com>
In-Reply-To: <20210428153542.2814175-1-Liam.Howlett@Oracle.com>
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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@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 =3D page_address(page);
=20
-		vma =3D find_vma(mm, msg->va);
+		vma =3D vma_lookup(mm, msg->va);
 		rc =3D -EINVAL;
=20
 		if (!vma || (msg->va !=3D vma->vm_start) || vma->vm_private_data)
--=20
2.30.2