In some extreme cases, such as the I/O pressure test, the CPU usage may be 100%, causing RCU stall. In this case, the printed information about current is not useful. Displays the number and usage of hard interrupts, soft interrupts, and context switches that are generated within half of the CPU stall timeout, can help us make a general judgment. In other cases, we can preliminarily determine whether an infinite loop occurs when local_irq, local_bh or preempt is disabled. Zhen Lei (3): sched: Add helper kstat_cpu_softirqs_sum() sched: Add helper nr_context_switches_cpu() rcu: Add RCU stall diagnosis information include/linux/kernel_stat.h | 12 +++++++++++ kernel/rcu/tree.h | 11 ++++++++++ kernel/rcu/tree_stall.h | 40 +++++++++++++++++++++++++++++++++++++ kernel/sched/core.c | 5 +++++ 4 files changed, 68 insertions(+) -- 2.25.1
