[libvirt] [PATCH 2 of 2] Use cgroup functions to set resource limits on LXC domains

[Daniel P. Berrange]

On Wed, Oct 01, 2008 at 01:19:04PM -0700, Dan Smith wrote:
> This patch adds code to the controller to set up a cgroup named after the
> domain name, set the memory limit, and restrict devices.  It also
> adds bits to lxc_driver to properly clean up the cgroup on domain death.
> 
> If virCgroupHaveSupport() says that no support is available, then we just
> allow the domain creation to proceed as it did before without resource
> controls in place.


> +
> +    rc = virCgroupForDomain(def, &cgroup);
> +    if (rc != 0) {
> +        fprintf(stderr, "Unable to create cgroup for %s\n", def->name);
> +        goto out;
> +    }

Should use lxcError() here - as things are setup by virExec(), calls to
lxcError() call to virRaiseError() which ultimately calls fprintf(). By
using lxcError() can we more easily change logging later if needed.

> +
> +    rc = virCgroupSetMemory(cgroup, def->maxmem);
> +    if (rc != 0)
> +        goto out;
> +
> +    rc = virCgroupDenyAllDevices(cgroup);
> +    if (rc != 0)
> +        goto out;
> +
> +    for (i = 0; devices[i].type != 0; i++) {
> +        struct cgroup_device_policy *dev = &devices[i];
> +        rc = virCgroupAllowDevice(cgroup,
> +                                  dev->type,
> +                                  dev->major,
> +                                  dev->minor);
> +        if (rc != 0)
> +            goto out;
> +    }
> +
> +    rc = virCgroupAddTask(cgroup, getpid());
> +out:
> +    virCgroupFree(&cgroup);
> +
> +    if (rc != 0)
> +        fprintf(stderr, "Failed to set lxc resources: %s\n", strerror(-rc));

Likewise here use lxcError().  

I think we need to virCgroupRemove() in the error path to cleanup
a partially constructed cgroup ?

Regards,
Daniel
-- 
|: Red Hat, Engineering, London   -o-   http://people.redhat.com/berrange/ :|
|: http://libvirt.org  -o-  http://virt-manager.org  -o-  http://ovirt.org :|
|: http://autobuild.org       -o-         http://search.cpan.org/~danberr/ :|
|: GnuPG: 7D3B9505  -o-  F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505 :|