From 8c4385024d31cb909ad84a2cafa5c83a4c5fab61 Mon Sep 17 00:00:00 2001 From: Avi Kivity Date: Mon, 16 Apr 2007 11:53:17 +0300 Subject: [PATCH] KVM: Retry sleeping allocation if atomic allocation fails This avoids -ENOMEM under memory pressure. Signed-off-by: Avi Kivity --- drivers/kvm/mmu.c | 26 +++++++++++++++++++++----- 1 file changed, 21 insertions(+), 5 deletions(-) diff --git a/drivers/kvm/mmu.c b/drivers/kvm/mmu.c index a368ea8297f3..c814394a966d 100644 --- a/drivers/kvm/mmu.c +++ b/drivers/kvm/mmu.c @@ -199,14 +199,15 @@ static int is_rmap_pte(u64 pte) } static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache *cache, - struct kmem_cache *base_cache, int min) + struct kmem_cache *base_cache, int min, + gfp_t gfp_flags) { void *obj; if (cache->nobjs >= min) return 0; while (cache->nobjs < ARRAY_SIZE(cache->objects)) { - obj = kmem_cache_zalloc(base_cache, GFP_NOWAIT); + obj = kmem_cache_zalloc(base_cache, gfp_flags); if (!obj) return -ENOMEM; cache->objects[cache->nobjs++] = obj; @@ -220,20 +221,35 @@ static void mmu_free_memory_cache(struct kvm_mmu_memory_cache *mc) kfree(mc->objects[--mc->nobjs]); } -static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu) +static int __mmu_topup_memory_caches(struct kvm_vcpu *vcpu, gfp_t gfp_flags) { int r; r = mmu_topup_memory_cache(&vcpu->mmu_pte_chain_cache, - pte_chain_cache, 4); + pte_chain_cache, 4, gfp_flags); if (r) goto out; r = mmu_topup_memory_cache(&vcpu->mmu_rmap_desc_cache, - rmap_desc_cache, 1); + rmap_desc_cache, 1, gfp_flags); out: return r; } +static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu) +{ + int r; + + r = __mmu_topup_memory_caches(vcpu, GFP_NOWAIT); + if (r < 0) { + spin_unlock(&vcpu->kvm->lock); + kvm_arch_ops->vcpu_put(vcpu); + r = __mmu_topup_memory_caches(vcpu, GFP_KERNEL); + kvm_arch_ops->vcpu_load(vcpu); + spin_lock(&vcpu->kvm->lock); + } + return r; +} + static void mmu_free_memory_caches(struct kvm_vcpu *vcpu) { mmu_free_memory_cache(&vcpu->mmu_pte_chain_cache); -- 2.39.5