kvm: memslots: track id_to_index changes during the insertion sort
This completes the optimization from the previous patch, by
removing the KVM_MEM_SLOTS_NUM-iteration loop from insert_memslot.
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index c0c2202..eae07f9 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -677,31 +677,31 @@
static void insert_memslot(struct kvm_memslots *slots,
struct kvm_memory_slot *new)
{
- int i = slots->id_to_index[new->id];
- struct kvm_memory_slot *old = id_to_memslot(slots, new->id);
+ int id = new->id;
+ int i = slots->id_to_index[id];
struct kvm_memory_slot *mslots = slots->memslots;
- if (new->npages == old->npages) {
- *old = *new;
- return;
- }
-
- while (1) {
- if (i < (KVM_MEM_SLOTS_NUM - 1) &&
- new->npages < mslots[i + 1].npages) {
- mslots[i] = mslots[i + 1];
- i++;
- } else if (i > 0 && new->npages > mslots[i - 1].npages) {
- mslots[i] = mslots[i - 1];
- i--;
+ WARN_ON(mslots[i].id != id);
+ if (new->npages != mslots[i].npages) {
+ if (new->npages < mslots[i].npages) {
+ while (i < KVM_MEM_SLOTS_NUM - 1 &&
+ new->npages < mslots[i + 1].npages) {
+ mslots[i] = mslots[i + 1];
+ slots->id_to_index[mslots[i].id] = i;
+ i++;
+ }
} else {
- mslots[i] = *new;
- break;
+ while (i > 0 &&
+ new->npages > mslots[i - 1].npages) {
+ mslots[i] = mslots[i - 1];
+ slots->id_to_index[mslots[i].id] = i;
+ i--;
+ }
}
}
- for (i = 0; i < KVM_MEM_SLOTS_NUM; i++)
- slots->id_to_index[slots->memslots[i].id] = i;
+ mslots[i] = *new;
+ slots->id_to_index[mslots[i].id] = i;
}
static void update_memslots(struct kvm_memslots *slots,