From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH] kvm: don not fail when cache is sufficient Date: Wed, 21 Apr 2010 11:45:26 +0300 Message-ID: <4BCEBB26.1060308@redhat.com> References: <4BC9790F.1070403@cn.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Cc: Marcelo Tosatti , LKML , kvm@vger.kernel.org To: Lai Jiangshan Return-path: In-Reply-To: <4BC9790F.1070403@cn.fujitsu.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org On 04/17/2010 12:02 PM, Lai Jiangshan wrote: > cleanup: don not fail when cache is sufficient > > Signed-off-by: Lai Jiangshan > --- > diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c > index c8c074c..90f666e 100644 > --- a/arch/x86/kvm/mmu.c > +++ b/arch/x86/kvm/mmu.c > @@ -304,7 +304,7 @@ static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache *cache, > while (cache->nobjs< ARRAY_SIZE(cache->objects)) { > obj = kmem_cache_zalloc(base_cache, GFP_KERNEL); > if (!obj) > - return -ENOMEM; > + return cache->nobjs>= min ? 0 : -ENOMEM; > cache->objects[cache->nobjs++] = obj; > } > return 0; > @@ -326,7 +326,7 @@ static int mmu_topup_memory_cache_page(struct kvm_mmu_memory_cache *cache, > while (cache->nobjs< ARRAY_SIZE(cache->objects)) { > page = alloc_page(GFP_KERNEL); > if (!page) > - return -ENOMEM; > + return cache->nobjs>= min ? 0 : -ENOMEM; > set_page_private(page, 0); > cache->objects[cache->nobjs++] = page_address(page); > } > > Have you ever observed this? My feeling is that if we're a few pages from -ENOMEM, it doesn't really matter if we die now or a few calls away. Note alloc_page() can call back into kvm via the shrinker to free pages, so an OOM will be external to kvm and we won't really be able to handle it. -- error compiling committee.c: too many arguments to function