Messages in this thread | | | Date | Wed, 13 Oct 2010 15:34:21 +0900 | From | KAMEZAWA Hiroyuki <> | Subject | Re: [PATCH v3 3/7] sched: throttle cfs_rq entities which exceed their local quota |
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On Tue, 12 Oct 2010 13:22:02 +0530 Bharata B Rao <bharata@linux.vnet.ibm.com> wrote:
> sched: throttle cfs_rq entities which exceed their local quota > > From: Paul Turner <pjt@google.com> > > In account_cfs_rq_quota() (via update_curr()) we track consumption versus a > cfs_rq's local quota and whether there is global quota available to continue > enabling it in the event we run out. > > This patch adds the required support for the latter case, throttling entities > until quota is available to run. Throttling dequeues the entity in question > and sends a reschedule to the owning cpu so that it can be evicted. > > The following restrictions apply to a throttled cfs_rq: > - It is dequeued from sched_entity hierarchy and restricted from being > re-enqueued. This means that new/waking children of this entity will be > queued up to it, but not past it. > - It does not contribute to weight calculations in tg_shares_up > - In the case that the cfs_rq of the cpu we are trying to pull from is throttled > it is is ignored by the loadbalancer in __load_balance_fair() and > move_one_task_fair(). > > Signed-off-by: Paul Turner <pjt@google.com> > Signed-off-by: Nikhil Rao <ncrao@google.com> > Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> > --- > kernel/sched.c | 12 ++++++++ > kernel/sched_fair.c | 70 ++++++++++++++++++++++++++++++++++++++++++++++++---- > 2 files changed, 76 insertions(+), 6 deletions(-) > > --- a/kernel/sched.c > +++ b/kernel/sched.c > @@ -387,6 +387,7 @@ struct cfs_rq { > #endif > #ifdef CONFIG_CFS_BANDWIDTH > u64 quota_assigned, quota_used; > + int throttled; > #endif > #endif > }; > @@ -1668,6 +1669,8 @@ static void update_group_shares_cpu(stru > } > } > > +static inline int cfs_rq_throttled(struct cfs_rq *cfs_rq); > +
I just curious that static-inline forward declaration is inlined ?
> /* > * Re-compute the task group their per cpu shares over the given domain. > * This needs to be done in a bottom-up fashion because the rq weight of a > @@ -1688,7 +1691,14 @@ static int tg_shares_up(struct task_grou > usd_rq_weight = per_cpu_ptr(update_shares_data, smp_processor_id()); > > for_each_cpu(i, sched_domain_span(sd)) { > - weight = tg->cfs_rq[i]->load.weight; > + /* > + * bandwidth throttled entities cannot contribute to load > + * balance > + */ > + if (!cfs_rq_throttled(tg->cfs_rq[i])) > + weight = tg->cfs_rq[i]->load.weight; > + else > + weight = 0;
cpu.share and bandwidth control can't be used simultaneously or... is this fair ? I'm not familiar with scheduler but this allows boost this tg. Could you add a brief documentaion of a spec/feature. in the next post ?
Thanks, -Kame
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