1*13578a08SGabriele MonacoMonitor stall 2*13578a08SGabriele Monaco============= 3*13578a08SGabriele Monaco 4*13578a08SGabriele Monaco- Name: stall - stalled task monitor 5*13578a08SGabriele Monaco- Type: per-task hybrid automaton 6*13578a08SGabriele Monaco- Author: Gabriele Monaco <gmonaco@redhat.com> 7*13578a08SGabriele Monaco 8*13578a08SGabriele MonacoDescription 9*13578a08SGabriele Monaco----------- 10*13578a08SGabriele Monaco 11*13578a08SGabriele MonacoThe stalled task (stall) monitor is a sample per-task timed monitor that checks 12*13578a08SGabriele Monacoif tasks are scheduled within a defined threshold after they are ready:: 13*13578a08SGabriele Monaco 14*13578a08SGabriele Monaco | 15*13578a08SGabriele Monaco | 16*13578a08SGabriele Monaco v 17*13578a08SGabriele Monaco #==========================# 18*13578a08SGabriele Monaco +-----------------> H dequeued H 19*13578a08SGabriele Monaco | #==========================# 20*13578a08SGabriele Monaco | | 21*13578a08SGabriele Monaco sched_switch_wait | sched_wakeup;reset(clk) 22*13578a08SGabriele Monaco | v 23*13578a08SGabriele Monaco | +--------------------------+ <+ 24*13578a08SGabriele Monaco | | enqueued | | sched_wakeup 25*13578a08SGabriele Monaco | | clk < threshold_jiffies | -+ 26*13578a08SGabriele Monaco | +--------------------------+ 27*13578a08SGabriele Monaco | | ^ 28*13578a08SGabriele Monaco | sched_switch_in sched_switch_preempt;reset(clk) 29*13578a08SGabriele Monaco | v | 30*13578a08SGabriele Monaco | +--------------------------+ 31*13578a08SGabriele Monaco +------------------ | running | 32*13578a08SGabriele Monaco +--------------------------+ 33*13578a08SGabriele Monaco ^ sched_switch_in | 34*13578a08SGabriele Monaco | sched_wakeup | 35*13578a08SGabriele Monaco +----------------------+ 36*13578a08SGabriele Monaco 37*13578a08SGabriele MonacoThe threshold can be configured as a parameter by either booting with the 38*13578a08SGabriele Monaco``stall.threshold_jiffies=<new value>`` argument or writing a new value to 39*13578a08SGabriele Monaco``/sys/module/stall/parameters/threshold_jiffies``. 40*13578a08SGabriele Monaco 41*13578a08SGabriele MonacoSpecification 42*13578a08SGabriele Monaco------------- 43*13578a08SGabriele MonacoGraphviz Dot file in tools/verification/models/stall.dot 44