lkml.org 
[lkml]   [2014]   [Nov]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH 1/3] kvm: memslots: track id_to_index changes during the insertion sort
On Fri, 14 Nov 2014 12:12:00 +0100
Paolo Bonzini <pbonzini@redhat.com> wrote:

> This completes the optimization from the previous patch, by
> removing the KVM_MEM_SLOTS_NUM-iteration loop from insert_memslot.
>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
> virt/kvm/kvm_main.c | 39 +++++++++++++++++++--------------------
> 1 file changed, 19 insertions(+), 20 deletions(-)
>
> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> index c0c2202e6c4f..c8ff99cc0ccb 100644
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
> @@ -677,31 +677,30 @@ static int kvm_create_dirty_bitmap(struct
> kvm_memory_slot *memslot) 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--;
> - } else {
> - mslots[i] = *new;
> - break;
> + WARN_ON(mslots[i].id != id);
> + if (new->npages != mslots[i].npages) {
> + while (1) {
> + if (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 if (i > 0 &&
> + new->npages > mslots[i -
> 1].npages) {
> + mslots[i] = mslots[i - 1];
> + slots->id_to_index[mslots[i].id] = i;
> + i--;
> + } else
> + break;
> }
> }
>
> - 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,

Reviewed-by: Igor Mammedov <imammedo@redhat.com>


\
 
 \ /
  Last update: 2014-11-14 15:01    [W:0.075 / U:0.140 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site