On 02/23/2016 10:58 AM, Henning Schild wrote:
> When using a hierarchy of cgroups we might want to add tasks just to
> the children cgroups but never to the parent. To make sure we do not
> use a parent cgroup by accident add a mechanism that lets us assert
> a correct implementation in cases we want such a hierarchy.
>
> i.e. for qemu cpusets we want all tasks in /vcpuX or /emulator, not
> in /.
>
> Signed-off-by: Henning Schild <henning.schild@xxxxxxxxxxx>
> ---
> src/libvirt_private.syms | 2 ++
> src/util/vircgroup.c | 19 +++++++++++++++++++
> src/util/vircgroup.h | 3 +++
> src/util/vircgrouppriv.h | 1 +
> 4 files changed, 25 insertions(+)
>
These aren't used until patch 9 - I think this should be closer to that
patch... That is introduce it just before you use it..
> diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
> index 83f6e2c..cf93d06 100644
> --- a/src/libvirt_private.syms
> +++ b/src/libvirt_private.syms
> @@ -1201,6 +1201,7 @@ virCgroupDenyDeviceMajor;
> virCgroupDenyDevicePath;
> virCgroupDetectMountsFromFile;
> virCgroupFree;
> +virCgroupGetAssertEmpty;
> virCgroupGetBlkioDeviceReadBps;
> virCgroupGetBlkioDeviceReadIops;
> virCgroupGetBlkioDeviceWeight;
> @@ -1245,6 +1246,7 @@ virCgroupNewThread;
> virCgroupPathOfController;
> virCgroupRemove;
> virCgroupRemoveRecursively;
> +virCgroupSetAssertEmpty;
> virCgroupSetBlkioDeviceReadBps;
> virCgroupSetBlkioDeviceReadIops;
> virCgroupSetBlkioDeviceWeight;
> diff --git a/src/util/vircgroup.c b/src/util/vircgroup.c
> index 0b65238..ad46dfc 100644
> --- a/src/util/vircgroup.c
> +++ b/src/util/vircgroup.c
> @@ -1197,6 +1197,15 @@ virCgroupAddTaskController(virCgroupPtr group, pid_t pid, int controller)
> return -1;
> }
>
> + if(group->assert_empty & (1 << controller)) {
should be :
if (group...
> + virReportError(VIR_ERR_INTERNAL_ERROR,
> + _("Controller '%s' is not supposed to contain any"
> + " tasks. group=%s pid=%d\n"),
> + virCgroupControllerTypeToString(controller),
> + group->path, pid);
> + return -1;
> + }
> +
> return virCgroupSetValueU64(group, controller, "tasks",
> (unsigned long long)pid);
> }
> @@ -1246,6 +1255,16 @@ virCgroupAddTaskStrController(virCgroupPtr group,
> return rc;
> }
>
Need to have some code comments regarding input and what these do...
> +void
> +virCgroupSetAssertEmpty(virCgroupPtr group, int mask) {
> + group->assert_empty = mask;
> +}
> +
> +int
> +virCgroupGetAssertEmpty(virCgroupPtr group) {
> + return group->assert_empty;
> +}
> +
>
You'll need to add the corresponding API in the "#else /*
!VIR_CGROUP_SUPPORTED */" area... Search on virCgroupAddTaskController -
you'll find a second entry in the module which reports a system error.
That's what you'll need to add for these
John
> /**
> * virCgroupMoveTask:
> diff --git a/src/util/vircgroup.h b/src/util/vircgroup.h
> index 63a9e1c..f244c24 100644
> --- a/src/util/vircgroup.h
> +++ b/src/util/vircgroup.h
> @@ -131,6 +131,9 @@ int virCgroupAddTaskController(virCgroupPtr group,
> pid_t pid,
> int controller);
>
> +void virCgroupSetAssertEmpty(virCgroupPtr group, int mask);
> +int virCgroupGetAssertEmpty(virCgroupPtr group);
> +
> int virCgroupMoveTask(virCgroupPtr src_group,
> virCgroupPtr dest_group);
>
> diff --git a/src/util/vircgrouppriv.h b/src/util/vircgrouppriv.h
> index 722863e..944d6ae 100644
> --- a/src/util/vircgrouppriv.h
> +++ b/src/util/vircgrouppriv.h
> @@ -44,6 +44,7 @@ struct virCgroupController {
>
> struct virCgroup {
> char *path;
> + int assert_empty;
>
> struct virCgroupController controllers[VIR_CGROUP_CONTROLLER_LAST];
> };
>
--
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