Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752207Ab1BVIMS (ORCPT ); Tue, 22 Feb 2011 03:12:18 -0500 Received: from cn.fujitsu.com ([222.73.24.84]:58120 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1751619Ab1BVIMR (ORCPT ); Tue, 22 Feb 2011 03:12:17 -0500 Message-ID: <4D637019.9070208@cn.fujitsu.com> Date: Tue, 22 Feb 2011 16:13:13 +0800 From: Xiao Guangrong User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.13) Gecko/20101209 Fedora/3.1.7-0.35.b3pre.fc14 Thunderbird/3.1.7 MIME-Version: 1.0 To: Avi Kivity CC: Marcelo Tosatti , LKML , KVM Subject: [PATCH 5/7] KVM: cache the last used slot References: <4D636EF8.60800@cn.fujitsu.com> In-Reply-To: <4D636EF8.60800@cn.fujitsu.com> X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.1FP4|July 25, 2010) at 2011-02-22 16:11:14, Serialize by Router on mailserver/fnst(Release 8.5.1FP4|July 25, 2010) at 2011-02-22 16:11:15, Serialize complete at 2011-02-22 16:11:15 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2026 Lines: 64 Cache the last used slot, the hit ratio is more than 35% during my test Signed-off-by: Xiao Guangrong --- include/linux/kvm_host.h | 1 + virt/kvm/kvm_main.c | 11 +++++++++-- 2 files changed, 10 insertions(+), 2 deletions(-) diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index f1963a4..7fbae16 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -225,6 +225,7 @@ struct kvm_memslots { int nmemslots; int used_slots; u64 generation; + struct kvm_memory_slot *slot_cache; struct kvm_memory_slot memslots[KVM_MEM_SLOTS_NUM]; struct kvm_memory_slot *slots_sort[KVM_MEM_SLOTS_NUM]; }; diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 0795426..4917d6a 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -643,15 +643,21 @@ static struct kvm_memory_slot *search_memslots(struct kvm_memslots *slots, gfn_t gfn) { int start = 0, end = slots->used_slots, idx; - struct kvm_memory_slot *memslot; + struct kvm_memory_slot *memslot = slots->slot_cache; + + if (memslot && gfn >= memslot->base_gfn && + gfn < memslot->base_gfn + memslot->npages) + return memslot; while (start < end) { idx = (start + end) / 2; memslot = slots->slots_sort[idx]; if (gfn >= memslot->base_gfn && - gfn < memslot->base_gfn + memslot->npages) + gfn < memslot->base_gfn + memslot->npages) { + slots->slot_cache = memslot; return memslot; + } if (memslot->base_gfn < gfn) start = idx + 1; @@ -684,6 +690,7 @@ void memslots_updated(struct kvm_memslots *slots, int slot_id) if (slot_id >= slots->nmemslots) slots->nmemslots = slot_id + 1; slots->generation++; + slots->slot_cache = NULL; sort_memslots(slots); } -- 1.7.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/