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authorTakuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp>2010-11-01 14:36:09 +0900
committerAvi Kivity <avi@redhat.com>2011-01-12 11:28:48 +0200
commit6f9e5c1702319e048a90e06e31b957fbbcecbe07 (patch)
tree335deee0e2351cdde480460200162dc055ef717e
parent515a01279a187415322a80736800a7d6325876ab (diff)
downloadlinux-6f9e5c1702319e048a90e06e31b957fbbcecbe07.tar.bz2
KVM: use kmalloc() for small dirty bitmaps
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. This will also make the logging start/stop faster. Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
-rw-r--r--virt/kvm/kvm_main.c13
1 files changed, 10 insertions, 3 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 27649fdaa007..9ce1079e8f89 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;
}
@@ -547,11 +551,14 @@ 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 = vzalloc(dirty_bytes);
+ else
+ memslot->dirty_bitmap = kzalloc(dirty_bytes, GFP_KERNEL);
+
if (!memslot->dirty_bitmap)
return -ENOMEM;
- memset(memslot->dirty_bitmap, 0, dirty_bytes);
memslot->dirty_bitmap_head = memslot->dirty_bitmap;
return 0;
}