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| author | Marcelo Tosatti <mtosatti@redhat.com> | 2008-09-16 20:54:47 -0300 |
|---|---|---|
| committer | Avi Kivity <avi@redhat.com> | 2008-10-15 14:25:06 +0200 |
| commit | 4c2155ce81c193788082d4b8cdbc26d79edebc58 (patch) | |
| tree | 5c028fe4a18c55b5c0e9c4e80be459dad3f96da7 /arch/x86/kvm/paging_tmpl.h | |
| parent | 777b3f49d297e387866604093b635e5bc9b9d2a6 (diff) | |
| download | linux-4c2155ce81c193788082d4b8cdbc26d79edebc58.tar.gz | |
KVM: switch to get_user_pages_fast
Convert gfn_to_pfn to use get_user_pages_fast, which can do lockless pagetable lookups on x86. Kernel compilation on 4-way guest is 3.7% faster on VMX. Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
Diffstat (limited to 'arch/x86/kvm/paging_tmpl.h')
| -rw-r--r-- | arch/x86/kvm/paging_tmpl.h | 8 |
1 files changed, 1 insertions, 7 deletions
diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h index b671f61be41e..6dd08e096e24 100644 --- a/arch/x86/kvm/paging_tmpl.h +++ b/arch/x86/kvm/paging_tmpl.h @@ -102,14 +102,10 @@ static bool FNAME(cmpxchg_gpte)(struct kvm *kvm, pt_element_t *table; struct page *page; - down_read(¤t->mm->mmap_sem); page = gfn_to_page(kvm, table_gfn); - up_read(¤t->mm->mmap_sem); table = kmap_atomic(page, KM_USER0); - ret = CMPXCHG(&table[index], orig_pte, new_pte); - kunmap_atomic(table, KM_USER0); kvm_release_page_dirty(page); @@ -418,7 +414,6 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr, return 0; } - down_read(¤t->mm->mmap_sem); if (walker.level == PT_DIRECTORY_LEVEL) { gfn_t large_gfn; large_gfn = walker.gfn & ~(KVM_PAGES_PER_HPAGE-1); @@ -428,9 +423,8 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr, } } mmu_seq = vcpu->kvm->mmu_notifier_seq; - /* implicit mb(), we'll read before PT lock is unlocked */ + smp_rmb(); pfn = gfn_to_pfn(vcpu->kvm, walker.gfn); - up_read(¤t->mm->mmap_sem); /* mmio */ if (is_error_pfn(pfn)) { |