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From: chenjinghuang To: Ingo Molnar , Peter Zijlstra , Juri Lelli , Vincent Guittot CC: Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Valentin Schneider , K Prateek Nayak , , Ridong Chen , Madadi Vineeth Reddy References: <20260625110323.2980246-1-chenjinghuang2@huawei.com> In-Reply-To: <20260625110323.2980246-1-chenjinghuang2@huawei.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit X-ClientProxiedBy: kwepems100002.china.huawei.com (7.221.188.206) To kwepemr500016.china.huawei.com (7.202.195.68) On 6/25/2026 7:03 PM, Chen Jinghuang wrote: > For example: > # cat /proc/sys/kernel/sched_rt_runtime_us > 950000 > # echo 940000 > /proc/sys/kernel/sched_rt_runtime_us > -bash: echo: write error: Invalid argument > Sorry, I forgot that sched_rt_runtime_us is currently set to 1000000, so it should be the following case: # cat /proc/sys/kernel/sched_rt_runtime_us 1000000 # echo 940000 > /proc/sys/kernel/sched_rt_runtime_us -bash: echo: write error: Invalid argument > With CONFIG_RT_GROUP_SCHED enabled, reducing the global RT quota > causes the unchanged root cgroup quota to exceed the new global limit. > The root cgroup quota should be updated accordingly when the global > quota changes. > > Adjust the root cgroup's RT quota whenever the global RT quota is > modified. > > Signed-off-by: Chen Jinghuang > Reviewed-by: Ridong Chen > Tested-by: Madadi Vineeth Reddy > --- > Change since v1: https://lore.kernel.org/all/20260320013419.2493925-1-chenjinghuang2@huawei.com/ > - Rebase the patch onto mainline. > --- > kernel/sched/rt.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c > index e474c31d8fe6..b1b082e365af 100644 > --- a/kernel/sched/rt.c > +++ b/kernel/sched/rt.c > @@ -2858,9 +2858,12 @@ static int sched_rt_global_validate(void) > #ifdef CONFIG_RT_GROUP_SCHED > if (!rt_group_sched_enabled()) > return 0; > + > + u64 period = global_rt_period(); > + u64 runtime = global_rt_runtime(); > > scoped_guard(mutex, &rt_constraints_mutex) > - return __rt_schedulable(NULL, 0, 0); > + return __rt_schedulable(&root_task_group, period, runtime); > #endif > return 0; > } Gently pingļ¼