diff options
| -rw-r--r-- | arch/x86/kvm/mmu.c | 34 |
1 files changed, 24 insertions, 10 deletions
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index ff39b85..33d7af5 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -178,6 +178,7 @@ 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; static struct kmem_cache *mmu_page_header_cache; +static struct percpu_counter kvm_total_used_mmu_pages; static u64 __read_mostly shadow_trap_nonpresent_pte; static u64 __read_mostly shadow_notrap_nonpresent_pte; @@ -971,6 +972,18 @@ static int is_empty_shadow_page(u64 *spt) } #endif +/* + * This value is the sum of all of the kvm instances's + * kvm->arch.n_used_mmu_pages values. We need a global, + * aggregate version in order to make the slab shrinker + * faster + */ +static inline void kvm_mod_used_mmu_pages(struct kvm *kvm, int nr) +{ + kvm->arch.n_used_mmu_pages += nr; + percpu_counter_add(&kvm_total_used_mmu_pages, nr); +} + static void kvm_mmu_free_page(struct kvm *kvm, struct kvm_mmu_page *sp) { ASSERT(is_empty_shadow_page(sp->spt)); @@ -980,7 +993,7 @@ static void kvm_mmu_free_page(struct kvm *kvm, struct kvm_mmu_page *sp) if (!sp->role.direct) __free_page(virt_to_page(sp->gfns)); kmem_cache_free(mmu_page_header_cache, sp); - --kvm->arch.n_used_mmu_pages; + kvm_mod_used_mmu_pages(kvm, -1); } static unsigned kvm_page_table_hashfn(gfn_t gfn) @@ -1003,7 +1016,7 @@ static struct kvm_mmu_page *kvm_mmu_alloc_page(struct kvm_vcpu *vcpu, bitmap_zero(sp->slot_bitmap, KVM_MEMORY_SLOTS + KVM_PRIVATE_MEM_SLOTS); sp->multimapped = 0; sp->parent_pte = parent_pte; - ++vcpu->kvm->arch.n_used_mmu_pages; + kvm_mod_used_mmu_pages(vcpu->kvm, +1); return sp; } @@ -3122,23 +3135,22 @@ static int mmu_shrink(struct shrinker *shrink, int nr_to_scan, gfp_t gfp_mask) { struct kvm *kvm; struct kvm *kvm_freed = NULL; - int cache_count = 0; + + if (nr_to_scan == 0) + goto out; spin_lock(&kvm_lock); list_for_each_entry(kvm, &vm_list, vm_list) { - int npages, idx, freed_pages; + int idx, freed_pages; LIST_HEAD(invalid_list); idx = srcu_read_lock(&kvm->srcu); spin_lock(&kvm->mmu_lock); - npages = kvm->arch.n_max_mmu_pages - - kvm_mmu_available_pages(kvm); - cache_count += npages; - if (!kvm_freed && nr_to_scan > 0 && npages > 0) { + if (!kvm_freed && nr_to_scan > 0 && + kvm->arch.n_used_mmu_pages > 0) { freed_pages = kvm_mmu_remove_some_alloc_mmu_pages(kvm, &invalid_list); - cache_count -= freed_pages; kvm_freed = kvm; } nr_to_scan--; @@ -3152,7 +3164,8 @@ static int mmu_shrink(struct shrinker *shrink, int nr_to_scan, gfp_t gfp_mask) spin_unlock(&kvm_lock); - return cache_count; +out: + return percpu_counter_read_positive(&kvm_total_used_mmu_pages); } static struct shrinker mmu_shrinker = { @@ -3195,6 +3208,7 @@ int kvm_mmu_module_init(void) if (!mmu_page_header_cache) goto nomem; + percpu_counter_init(&kvm_total_used_mmu_pages, 0); register_shrinker(&mmu_shrinker); return 0; |
