• Frederic Weisbecker's avatar
    sched: Keep at least 1 tick per second for active dynticks tasks · 265f22a9
    Frederic Weisbecker authored
    The scheduler doesn't yet fully support environments
    with a single task running without a periodic tick.
    
    In order to ensure we still maintain the duties of scheduler_tick(),
    keep at least 1 tick per second.
    
    This makes sure that we keep the progression of various scheduler
    accounting and background maintainance even with a very low granularity.
    Examples include cpu load, sched average, CFS entity vruntime,
    avenrun and events such as load balancing, amongst other details
    handled in sched_class::task_tick().
    
    This limitation will be removed in the future once we get
    these individual items to work in full dynticks CPUs.
    Suggested-by: default avatarIngo Molnar <mingo@kernel.org>
    Signed-off-by: default avatarFrederic Weisbecker <fweisbec@gmail.com>
    Cc: Christoph Lameter <cl@linux.com>
    Cc: Hakan Akkan <hakanakkan@gmail.com>
    Cc: Ingo Molnar <mingo@kernel.org>
    Cc: Kevin Hilman <khilman@linaro.org>
    Cc: Li Zhong <zhong@linux.vnet.ibm.com>
    Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
    Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
    Cc: Peter Zijlstra <peterz@infradead.org>
    Cc: Steven Rostedt <rostedt@goodmis.org>
    Cc: Thomas Gleixner <tglx@linutronix.de>
    265f22a9
tick-sched.c 29.6 KB