| From d7444794a02ff655eda87e3cc54e86b940e7736f Mon Sep 17 00:00:00 2001 |
| From: Christian Borntraeger <borntraeger@de.ibm.com> |
| Date: Fri, 19 Feb 2016 13:11:46 +0100 |
| Subject: KVM: async_pf: do not warn on page allocation failures |
| |
| From: Christian Borntraeger <borntraeger@de.ibm.com> |
| |
| commit d7444794a02ff655eda87e3cc54e86b940e7736f upstream. |
| |
| In async_pf we try to allocate with NOWAIT to get an element quickly |
| or fail. This code also handle failures gracefully. Lets silence |
| potential page allocation failures under load. |
| |
| qemu-system-s39: page allocation failure: order:0,mode:0x2200000 |
| [...] |
| Call Trace: |
| ([<00000000001146b8>] show_trace+0xf8/0x148) |
| [<000000000011476a>] show_stack+0x62/0xe8 |
| [<00000000004a36b8>] dump_stack+0x70/0x98 |
| [<0000000000272c3a>] warn_alloc_failed+0xd2/0x148 |
| [<000000000027709e>] __alloc_pages_nodemask+0x94e/0xb38 |
| [<00000000002cd36a>] new_slab+0x382/0x400 |
| [<00000000002cf7ac>] ___slab_alloc.constprop.30+0x2dc/0x378 |
| [<00000000002d03d0>] kmem_cache_alloc+0x160/0x1d0 |
| [<0000000000133db4>] kvm_setup_async_pf+0x6c/0x198 |
| [<000000000013dee8>] kvm_arch_vcpu_ioctl_run+0xd48/0xd58 |
| [<000000000012fcaa>] kvm_vcpu_ioctl+0x372/0x690 |
| [<00000000002f66f6>] do_vfs_ioctl+0x3be/0x510 |
| [<00000000002f68ec>] SyS_ioctl+0xa4/0xb8 |
| [<0000000000781c5e>] system_call+0xd6/0x264 |
| [<000003ffa24fa06a>] 0x3ffa24fa06a |
| |
| Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> |
| Reviewed-by: Dominik Dingel <dingel@linux.vnet.ibm.com> |
| Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| virt/kvm/async_pf.c | 2 +- |
| 1 file changed, 1 insertion(+), 1 deletion(-) |
| |
| --- a/virt/kvm/async_pf.c |
| +++ b/virt/kvm/async_pf.c |
| @@ -152,7 +152,7 @@ int kvm_setup_async_pf(struct kvm_vcpu * |
| * do alloc nowait since if we are going to sleep anyway we |
| * may as well sleep faulting in page |
| */ |
| - work = kmem_cache_zalloc(async_pf_cache, GFP_NOWAIT); |
| + work = kmem_cache_zalloc(async_pf_cache, GFP_NOWAIT | __GFP_NOWARN); |
| if (!work) |
| return 0; |
| |
