Re: [PATCH 3/3] kvm mmu: alloc shadow pages with __GFP_ZERO

[Marcelo Tosatti <mtosatti@redhat.com>]

On Wed, Feb 18, 2009 at 02:54:37PM +0100, Joerg Roedel wrote:
> > Adding __GFP_ZERO here will cause us to clear the page twice, which is wasteful.
> 
> The assertion which the attached patch removes fails sometimes. Removing
> this assertion is the alternative solution to this problem ;-)
> 

From: Joerg Roedel <joerg.roedel@amd.com>
Date: Wed, 18 Feb 2009 14:51:13 +0100
Subject: [PATCH] kvm mmu: remove assertion in kvm_mmu_alloc_page

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
Acked-by: Marcelo Tosatti <mtosatti@redhat.com>

---
 arch/x86/kvm/mmu.c |    1 -
 1 files changed, 0 insertions(+), 1 deletions(-)
 
 diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
 index d93ecec..b226973 100644
 --- a/arch/x86/kvm/mmu.c
 +++ b/arch/x86/kvm/mmu.c
 @@ -802,7 +802,6 @@ static struct kvm_mmu_page *kvm_mmu_alloc_page(struct kvm_vcpu *vcpu,
  	set_page_private(virt_to_page(sp->spt), (unsigned long)sp);
  	list_add(&sp->link, &vcpu->kvm->arch.active_mmu_pages);
  	INIT_LIST_HEAD(&sp->oos_link);
 -	ASSERT(is_empty_shadow_page(sp->spt));
  	bitmap_zero(sp->slot_bitmap, KVM_MEMORY_SLOTS + KVM_PRIVATE_MEM_SLOTS);
  	sp->multimapped = 0;
  	sp->parent_pte = parent_pte;