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| author | Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> | 2010-11-01 14:36:09 +0900 |
|---|---|---|
| committer | Avi Kivity <avi@redhat.com> | 2011-01-12 11:28:48 +0200 |
| commit | 6f9e5c1702319e048a90e06e31b957fbbcecbe07 (patch) | |
| tree | 335deee0e2351cdde480460200162dc055ef717e /virt | |
| parent | 515a01279a187415322a80736800a7d6325876ab (diff) | |
| download | lwn-6f9e5c1702319e048a90e06e31b957fbbcecbe07.tar.gz lwn-6f9e5c1702319e048a90e06e31b957fbbcecbe07.zip | |
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>
Diffstat (limited to 'virt')
| -rw-r--r-- | virt/kvm/kvm_main.c | 13 |
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; } |