Currently we are using vmalloc() for all dirty bitmaps even if
they are small enough, say less than K bytes.
We use kmalloc() if dirty bitmap size is less than or equal to
PAGE_SIZE so that we can avoid vmalloc area usage for VGA.
Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@xxxxxxxxxxxxx>
---
virt/kvm/kvm_main.c | 12 ++++++++++--
1 files changed, 10 insertions(+), 2 deletions(-)
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 81bc1c7..236f560 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -449,7 +449,11 @@ static void kvm_destroy_dirty_bitmap(struct kvm_memory_slot *memslot)
if (!memslot->dirty_bitmap)
return;
- vfree(memslot->dirty_bitmap_head);
+ if (2 * kvm_dirty_bitmap_bytes(memslot) > PAGE_SIZE)
+ vfree(memslot->dirty_bitmap_head);
+ else
+ kfree(memslot->dirty_bitmap_head);
+
memslot->dirty_bitmap = NULL;
memslot->dirty_bitmap_head = NULL;
}
@@ -547,7 +551,11 @@ static int kvm_create_dirty_bitmap(struct kvm_memory_slot *memslot)
{
unsigned long dirty_bytes = 2 * kvm_dirty_bitmap_bytes(memslot);
- memslot->dirty_bitmap = vmalloc(dirty_bytes);
+ if (dirty_bytes > PAGE_SIZE)
+ memslot->dirty_bitmap = vmalloc(dirty_bytes);
+ else
+ memslot->dirty_bitmap = kmalloc(dirty_bytes, GFP_KERNEL);
+
if (!memslot->dirty_bitmap)
return -ENOMEM;
--
1.7.0.4
--
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