List the wait resources and scheduler waits from OS
Got the below script from PSS when we were dealing with a support case to identify the root cause for Scheduler errors during a performance loss & exception errors exercise:
select
scheduler_id,
current_tasks_count,
runnable_tasks_count,
current_workers_count,
active_workers_count,
work_queue_count,
load_factor
from sys.dm_os_schedulers
where scheduler_id < 255
In this regard highlight on SchedulerRelatedDMVs blog from Linchi shea. Also another reason to take advantage of SQLOS and make use of PowerShell script from operating system.