[v2] KVM: x86/mmu: Optimize kvm_zap_obsolete_pages execution time

Commit Message

Hao Peng July 31, 2024, 9:27 a.m. UTC

From: Peng Hao <[e-mail]>

Optimize function execution by checking whether the active_mmu_pages
list is empty.

Signed-off-by: Peng Hao <[e-mail]>
---
 arch/x86/kvm/mmu/mmu.c | 3 +++
 1 file changed, 3 insertions(+)

Patch

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 901be9e420a4..e8abf4387d1e 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -6353,6 +6353,9 @@  static void kvm_zap_obsolete_pages(struct kvm *kvm)
 	int nr_zapped, batch = 0;
 	bool unstable;
 
+	if (list_empty(&kvm->arch.active_mmu_pages))
+		return;
+
 restart:
 	list_for_each_entry_safe_reverse(sp, node,
 	      &kvm->arch.active_mmu_pages, link) {