From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755210Ab1KXJmC (ORCPT ); Thu, 24 Nov 2011 04:42:02 -0500 Received: from mail-iy0-f174.google.com ([209.85.210.174]:65289 "EHLO mail-iy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754958Ab1KXJmA (ORCPT ); Thu, 24 Nov 2011 04:42:00 -0500 Message-ID: <4ECE1162.9080701@gmail.com> Date: Thu, 24 Nov 2011 17:41:54 +0800 From: Xiao Guangrong User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:8.0) Gecko/20111115 Thunderbird/8.0 MIME-Version: 1.0 To: Avi Kivity CC: Marcelo Tosatti , Xiao Guangrong , LKML , KVM Subject: [PATCH v3 6/6] KVM: introduce a table to map slot id to index in memslots array References: <4ECE1037.4060300@gmail.com> In-Reply-To: <4ECE1037.4060300@gmail.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Xiao Guangrong The operation of getting dirty log is frequent when framebuffer-based displays are used(for example, Xwindow), so, we introduce a mapping table to speed up id_to_memslot() Signed-off-by: Xiao Guangrong --- include/linux/kvm_host.h | 13 +++++++------ virt/kvm/kvm_main.c | 7 ++++++- 2 files changed, 13 insertions(+), 7 deletions(-) diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 9efdf5c..8c5c303 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -239,6 +239,8 @@ struct kvm_irq_routing_table {}; struct kvm_memslots { u64 generation; struct kvm_memory_slot memslots[KVM_MEM_SLOTS_NUM]; + /* The mapping table from slot id to the index in memslots[]. */ + int id_to_index[KVM_MEM_SLOTS_NUM]; }; struct kvm { @@ -341,14 +343,13 @@ static inline struct kvm_memslots *kvm_memslots(struct kvm *kvm) static inline struct kvm_memory_slot * id_to_memslot(struct kvm_memslots *slots, int id) { - int i; + int index = slots->id_to_index[id]; + struct kvm_memory_slot *slot; - for (i = 0; i < KVM_MEM_SLOTS_NUM; i++) - if (slots->memslots[i].id == id) - return &slots->memslots[i]; + slot = &slots->memslots[index]; - WARN_ON(1); - return NULL; + WARN_ON(slot->id != id); + return slot; } #define HPA_MSB ((sizeof(hpa_t) * 8) - 1) diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 6e8eb15..e289486 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -446,7 +446,7 @@ static void kvm_init_memslots_id(struct kvm *kvm) struct kvm_memslots *slots = kvm->memslots; for (i = 0; i < KVM_MEM_SLOTS_NUM; i++) - slots->memslots[i].id = i; + slots->id_to_index[i] = slots->memslots[i].id = i; } static struct kvm *kvm_create_vm(void) @@ -674,8 +674,13 @@ static int cmp_memslot(const void *slot1, const void *slot2) */ static void sort_memslots(struct kvm_memslots *slots) { + int i; + sort(slots->memslots, KVM_MEM_SLOTS_NUM, sizeof(struct kvm_memory_slot), cmp_memslot, NULL); + + for (i = 0; i < KVM_MEM_SLOTS_NUM; i++) + slots->id_to_index[slots->memslots[i].id] = i; } void update_memslots(struct kvm_memslots *slots, struct kvm_memory_slot *new) -- 1.7.7.3