linux-kernel - [PATCH 5/10] KVM: MMU: move mmu pages calculated out of mmu lock

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Date:	Fri, 04 Mar 2011 18:59:21 +0800
From:	Xiao Guangrong <xiaoguangrong@...fujitsu.com>
To:	Avi Kivity <avi@...hat.com>
CC:	Marcelo Tosatti <mtosatti@...hat.com>,
	LKML <linux-kernel@...r.kernel.org>, KVM <kvm@...r.kernel.org>
Subject: [PATCH 5/10] KVM: MMU: move mmu pages calculated out of mmu lock

kvm_mmu_calculate_mmu_pages need to walk all memslots and it's protected by
kvm->slots_lock, so move it out of mmu spinlock

Signed-off-by: Xiao Guangrong <xiaoguangrong@...fujitsu.com>
---
 arch/x86/kvm/x86.c |   10 +++++-----
 1 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 785ae0c..b9c2b8e 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -6105,7 +6105,7 @@ void kvm_arch_commit_memory_region(struct kvm *kvm,
 				int user_alloc)
 {
 
-	int npages = mem->memory_size >> PAGE_SHIFT;
+	int nr_mmu_pages = 0, npages = mem->memory_size >> PAGE_SHIFT;
 
 	if (!user_alloc && !old.user_alloc && old.rmap && !npages) {
 		int ret;
@@ -6120,12 +6120,12 @@ void kvm_arch_commit_memory_region(struct kvm *kvm,
 			       "failed to munmap memory\n");
 	}
 
+	if (!kvm->arch.n_requested_mmu_pages)
+		nr_mmu_pages = kvm_mmu_calculate_mmu_pages(kvm);
+
 	spin_lock(&kvm->mmu_lock);
-	if (!kvm->arch.n_requested_mmu_pages) {
-		unsigned int nr_mmu_pages = kvm_mmu_calculate_mmu_pages(kvm);
+	if (nr_mmu_pages)
 		kvm_mmu_change_mmu_pages(kvm, nr_mmu_pages);
-	}
-
 	kvm_mmu_slot_remove_write_access(kvm, mem->slot);
 	spin_unlock(&kvm->mmu_lock);
 }
-- 
1.7.4

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