Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760374Ab0FKNiv (ORCPT ); Fri, 11 Jun 2010 09:38:51 -0400 Received: from cn.fujitsu.com ([222.73.24.84]:50875 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1760314Ab0FKNit (ORCPT ); Fri, 11 Jun 2010 09:38:49 -0400 Message-ID: <4C123B93.7060803@cn.fujitsu.com> Date: Fri, 11 Jun 2010 21:35:15 +0800 From: Xiao Guangrong User-Agent: Thunderbird 2.0.0.24 (Windows/20100228) MIME-Version: 1.0 To: Avi Kivity CC: Marcelo Tosatti , LKML , KVM list Subject: [PATCH 7/7] KVM: MMU: don't walk every parent pages while mark unsync References: <4C1239EE.3090904@cn.fujitsu.com> In-Reply-To: <4C1239EE.3090904@cn.fujitsu.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 Content-Length: 3531 Lines: 119 While we mark the parent's unsync_child_bitmap, if the parent is already unsynced, it no need walk it's parent, it can reduce some unnecessary workload Signed-off-by: Xiao Guangrong --- arch/x86/kvm/mmu.c | 61 ++++++++++++++------------------------------------- 1 files changed, 17 insertions(+), 44 deletions(-) diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index eb20682..a92863f 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -175,7 +175,7 @@ struct kvm_shadow_walk_iterator { shadow_walk_okay(&(_walker)); \ shadow_walk_next(&(_walker))) -typedef int (*mmu_parent_walk_fn) (struct kvm_mmu_page *sp); +typedef void (*mmu_parent_walk_fn) (struct kvm_mmu_page *sp, u64 *spte); static struct kmem_cache *pte_chain_cache; static struct kmem_cache *rmap_desc_cache; @@ -1024,7 +1024,6 @@ static void mmu_page_remove_parent_pte(struct kvm_mmu_page *sp, BUG(); } - static void mmu_parent_walk(struct kvm_mmu_page *sp, mmu_parent_walk_fn fn) { struct kvm_pte_chain *pte_chain; @@ -1034,63 +1033,37 @@ static void mmu_parent_walk(struct kvm_mmu_page *sp, mmu_parent_walk_fn fn) if (!sp->multimapped && sp->parent_pte) { parent_sp = page_header(__pa(sp->parent_pte)); - fn(parent_sp); - mmu_parent_walk(parent_sp, fn); + fn(parent_sp, sp->parent_pte); return; } + hlist_for_each_entry(pte_chain, node, &sp->parent_ptes, link) for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i) { - if (!pte_chain->parent_ptes[i]) + u64 *spte = pte_chain->parent_ptes[i]; + + if (!spte) break; - parent_sp = page_header(__pa(pte_chain->parent_ptes[i])); - fn(parent_sp); - mmu_parent_walk(parent_sp, fn); + parent_sp = page_header(__pa(spte)); + fn(parent_sp, spte); } } -static void kvm_mmu_update_unsync_bitmap(u64 *spte) +static void mark_unsync(struct kvm_mmu_page *sp, u64 *spte); +static void kvm_mmu_mark_parents_unsync(struct kvm_mmu_page *sp) { - unsigned int index; - struct kvm_mmu_page *sp = page_header(__pa(spte)); - - index = spte - sp->spt; - if (!__test_and_set_bit(index, sp->unsync_child_bitmap)) - sp->unsync_children++; - WARN_ON(!sp->unsync_children); + mmu_parent_walk(sp, mark_unsync); } -static void kvm_mmu_update_parents_unsync(struct kvm_mmu_page *sp) +static void mark_unsync(struct kvm_mmu_page *sp, u64 *spte) { - struct kvm_pte_chain *pte_chain; - struct hlist_node *node; - int i; + unsigned int index; - if (!sp->parent_pte) + index = spte - sp->spt; + if (__test_and_set_bit(index, sp->unsync_child_bitmap)) return; - - if (!sp->multimapped) { - kvm_mmu_update_unsync_bitmap(sp->parent_pte); + if (sp->unsync_children++) return; - } - - hlist_for_each_entry(pte_chain, node, &sp->parent_ptes, link) - for (i = 0; i < NR_PTE_CHAIN_ENTRIES; ++i) { - if (!pte_chain->parent_ptes[i]) - break; - kvm_mmu_update_unsync_bitmap(pte_chain->parent_ptes[i]); - } -} - -static int unsync_walk_fn(struct kvm_mmu_page *sp) -{ - kvm_mmu_update_parents_unsync(sp); - return 1; -} - -static void kvm_mmu_mark_parents_unsync(struct kvm_mmu_page *sp) -{ - mmu_parent_walk(sp, unsync_walk_fn); - kvm_mmu_update_parents_unsync(sp); + kvm_mmu_mark_parents_unsync(sp); } static void nonpaging_prefetch_page(struct kvm_vcpu *vcpu, -- 1.6.1.2 -- 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/