[PATCH] KVM x86: remove memset, use vzalloc and don't assign thesame value to a variable twice

From: Jesper Juhl
Date: Sat Oct 30 2010 - 14:42:12 EST


Hi,

We can improve kvm_vm_ioctl_get_dirty_log() slightly by using vzalloc()
rather than first allocating and then manually zero the memory with
memset(). Also, while I was looking at this I noticed that we assign
-ENOMEM to the 'r' variable twice even though none of the code inbetween
the two assignments can change 'r', so I removed the second assignment.

Patch has been compile tested only.

Please consider merging and please CC me on all replies as I'm not
subscribed to the kvm mailing list.


Signed-off-by: Jesper Juhl <jj@xxxxxxxxxxxxx>
---
x86.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 2288ad8..29f9c0a 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3174,12 +3174,10 @@ int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
spin_unlock(&kvm->mmu_lock);

r = -ENOMEM;
- dirty_bitmap = vmalloc(n);
+ dirty_bitmap = vzalloc(n);
if (!dirty_bitmap)
goto out;
- memset(dirty_bitmap, 0, n);

- r = -ENOMEM;
slots = kzalloc(sizeof(struct kvm_memslots), GFP_KERNEL);
if (!slots) {
vfree(dirty_bitmap);


--
Jesper Juhl <jj@xxxxxxxxxxxxx> http://www.chaosbits.net/
Plain text mails only, please http://www.expita.com/nomime.html
Don't top-post http://www.catb.org/~esr/jargon/html/T/top-post.html

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/