kvm: Add memcg accounting to KVM allocations
There are many KVM kernel memory allocations which are tied to the life of
the VM process and should be charged to the VM process's cgroup. If the
allocations aren't tied to the process, the OOM killer will not know
that killing the process will free the associated kernel memory.
Add __GFP_ACCOUNT flags to many of the allocations which are not yet being
charged to the VM process's cgroup.
Tested:
Ran all kvm-unit-tests on a 64 bit Haswell machine, the patch
introduced no new failures.
Ran a kernel memory accounting test which creates a VM to touch
memory and then checks that the kernel memory allocated for the
process is within certain bounds.
With this patch we account for much more of the vmalloc and slab memory
allocated for the VM.
There remain a few allocations which should be charged to the VM's
cgroup but are not. In they include:
vcpu->run
kvm->coalesced_mmio_ring
There allocations are unaccounted in this patch because they are mapped
to userspace, and accounting them to a cgroup causes problems. This
should be addressed in a future patch.
Signed-off-by: Ben Gardon <bgardon@google.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/virt/kvm/vfio.c b/virt/kvm/vfio.c
index d99850c..524cbd2 100644
--- a/virt/kvm/vfio.c
+++ b/virt/kvm/vfio.c
@@ -219,7 +219,7 @@ static int kvm_vfio_set_group(struct kvm_device *dev, long attr, u64 arg)
}
}
- kvg = kzalloc(sizeof(*kvg), GFP_KERNEL);
+ kvg = kzalloc(sizeof(*kvg), GFP_KERNEL_ACCOUNT);
if (!kvg) {
mutex_unlock(&kv->lock);
kvm_vfio_group_put_external_user(vfio_group);
@@ -405,7 +405,7 @@ static int kvm_vfio_create(struct kvm_device *dev, u32 type)
if (tmp->ops == &kvm_vfio_ops)
return -EBUSY;
- kv = kzalloc(sizeof(*kv), GFP_KERNEL);
+ kv = kzalloc(sizeof(*kv), GFP_KERNEL_ACCOUNT);
if (!kv)
return -ENOMEM;