On Tue, Oct 27, 2020 at 11:28:51AM +0100, Sebastian Andrzej Siewior wrote:
> Is it running as a RT task?
root@c2d:~/rt-tests# ./pi_stress
Starting PI Stress Test
Number of thread groups: 1
Duration of test run: infinite
Number of inversions per group: unlimited
Admin thread SCHED_FIFO priority 4
1 groups of 3 threads will be created
High thread SCHED_FIFO priority 3
Med thread SCHED_FIFO priority 2
Low thread SCHED_FIFO priority 1
It says so, let me double check if those task really run with SCHED_FIFO.
> Do you have RCU-boosting enabled?
Yes
#
# RCU Subsystem
#
CONFIG_TREE_RCU=y
CONFIG_PREEMPT_RCU=y
CONFIG_RCU_EXPERT=y
CONFIG_SRCU=y
CONFIG_TREE_SRCU=y
CONFIG_TASKS_RCU_GENERIC=y
CONFIG_TASKS_RCU=y
CONFIG_TASKS_RUDE_RCU=y
CONFIG_RCU_STALL_COMMON=y
CONFIG_RCU_NEED_SEGCBLIST=y
CONFIG_RCU_FANOUT=64
CONFIG_RCU_FANOUT_LEAF=16
CONFIG_RCU_BOOST=y
CONFIG_RCU_BOOST_DELAY=500
CONFIG_RCU_NOCB_CPU=y
# CONFIG_TASKS_TRACE_RCU_READ_MB is not set
# end of RCU Subsystem
> Otherwise it looks that if you throw enough non-RT load on the system,
> RCU can not catch up which does not sound good.
I think this is what Clark tried to tell me. If I understood him
correctly the test tool is not correct though.
