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

Paul Turner
2011-06-22T06:58:15Z

On Tue, Jun 21, 2011 at 10:43 PM, Bharata B Rao
<bharata@linux.vnet.ibm.com> wrote:
> 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.
>

Yup! Thanks

> Regards,
> Bharata.
>