Re: [patch 04/16] sched: validate CFS quota hierarchies

Bharata B Rao
2011-06-22T05:43:45Z

On Tue, Jun 21, 2011 at 12:16:53AM -0700, Paul Turner wrote:
> Add constraints validation for CFS bandwidth hierarchies.
>
> Validate that:
> max(child bandwidth) <= parent_bandwidth
>
> In a quota limited hierarchy, an unconstrained entity
> (e.g. bandwidth==RUNTIME_INF) inherits the bandwidth of its parent.
>
> This constraint is chosen over sum(child_bandwidth) as notion of over-commit is
> valuable within SCHED_OTHER. Some basic code from the RT case is re-factored
> for reuse.
>
> Signed-off-by: Paul Turner <pjt@google.com>
>
> ---
> kernel/sched.c | 109 ++++++++++++++++++++++++++++++++++++++++++++++++++-------
> 1 file changed, 96 insertions(+), 13 deletions(-)
>
> Index: tip/kernel/sched.c
> ===================================================================
> --- tip.orig/kernel/sched.c
> +++ tip/kernel/sched.c
> @@ -249,6 +249,7 @@ struct cfs_bandwidth {
> raw_spinlock_t lock;
> ktime_t period;
> u64 quota;
> + s64 hierarchal_quota;

You mean hierarchical I suppose.

Regards,
Bharata.