[RFC PATCH v2 07/12] rv: Adapt the sco monitor to the new set_state
From: Gabriele Monaco <gmonaco@redhat.com>
Date: 2025-05-14 08:44:13
Also in:
linux-doc, lkml
Subsystem:
documentation, runtime verification (rv), the rest, tracing · Maintainers:
Jonathan Corbet, Steven Rostedt, Gabriele Monaco, Linus Torvalds, Masami Hiramatsu
The sched_set_state tracepoint changed prototype adding a new argument, this argument can differentiate between an explicit set_state called by a task and a set state to runnable by the scheduler due to a pending signal. Adapt the handlers prototypes for the sco monitor. Expand the model to handle the new set_state flavour, the monitor was making sure set state happens only outside of the scheduler, if the event occurs with the new argument (from_signal) set to true, we instead expect it to be inside the scheduler. Signed-off-by: Gabriele Monaco <gmonaco@redhat.com> --- Documentation/trace/rv/monitor_sched.rst | 35 +++++++++++++----------- kernel/trace/rv/monitors/sco/sco.c | 8 ++++-- kernel/trace/rv/monitors/sco/sco.h | 6 ++-- tools/verification/models/sched/sco.dot | 1 + 4 files changed, 30 insertions(+), 20 deletions(-)
diff --git a/Documentation/trace/rv/monitor_sched.rst b/Documentation/trace/rv/monitor_sched.rst
index 24b2c62a3bc2..6f76bba94d9f 100644
--- a/Documentation/trace/rv/monitor_sched.rst
+++ b/Documentation/trace/rv/monitor_sched.rst@@ -64,22 +64,25 @@ Monitor sco ~~~~~~~~~~~ The scheduling context operations (sco) monitor ensures changes in a task state -happen only in thread context:: - - - | - | - v - sched_set_state +------------------+ - +------------------ | | - | | thread_context | - +-----------------> | | <+ - +------------------+ | - | | - | schedule_entry | schedule_exit - v | - | - scheduling_context -+ +happen only in thread context, the only exception is a special kind of set +state that occurs if a task about to sleep has a pending signal. This set state +is not called by the thread but by the scheduler itself:: + + | + | + v + sched_set_state +------------------+ + +---------------------------------- | | + | | thread_context | + +---------------------------------> | | <+ + +------------------+ | + | | + | schedule_entry | schedule_exit + v | + sched_set_state_runnable_signal | + +---------------------------------- | + | scheduling_context | + +---------------------------------> -+ Monitor snroc ~~~~~~~~~~~~~
diff --git a/kernel/trace/rv/monitors/sco/sco.c b/kernel/trace/rv/monitors/sco/sco.c
index 66f4639d46ac..6457ff2469d0 100644
--- a/kernel/trace/rv/monitors/sco/sco.c
+++ b/kernel/trace/rv/monitors/sco/sco.c@@ -19,9 +19,13 @@ static struct rv_monitor rv_sco; DECLARE_DA_MON_PER_CPU(sco, unsigned char); -static void handle_sched_set_state(void *data, struct task_struct *tsk, int state) +static void handle_sched_set_state(void *data, struct task_struct *tsk, + int state, bool from_signal) { - da_handle_start_event_sco(sched_set_state_sco); + if (from_signal) + da_handle_event_sco(sched_set_state_runnable_signal_sco); + else + da_handle_start_event_sco(sched_set_state_sco); } static void handle_schedule_entry(void *data, bool preempt, unsigned long ip)
diff --git a/kernel/trace/rv/monitors/sco/sco.h b/kernel/trace/rv/monitors/sco/sco.h
index 7a4c1f2d5ca1..302750687f9c 100644
--- a/kernel/trace/rv/monitors/sco/sco.h
+++ b/kernel/trace/rv/monitors/sco/sco.h@@ -15,6 +15,7 @@ enum states_sco { enum events_sco { sched_set_state_sco = 0, + sched_set_state_runnable_signal_sco, schedule_entry_sco, schedule_exit_sco, event_max_sco
@@ -35,12 +36,13 @@ static const struct automaton_sco automaton_sco = { }, .event_names = { "sched_set_state", + "sched_set_state_runnable_signal", "schedule_entry", "schedule_exit" }, .function = { - { thread_context_sco, scheduling_context_sco, INVALID_STATE }, - { INVALID_STATE, INVALID_STATE, thread_context_sco }, + { thread_context_sco, INVALID_STATE, scheduling_context_sco, INVALID_STATE }, + { INVALID_STATE, scheduling_context_sco, INVALID_STATE, thread_context_sco }, }, .initial_state = thread_context_sco, .final_states = { 1, 0 },
diff --git a/tools/verification/models/sched/sco.dot b/tools/verification/models/sched/sco.dot
index 20b0e3b449a6..4e44ed58c62a 100644
--- a/tools/verification/models/sched/sco.dot
+++ b/tools/verification/models/sched/sco.dot@@ -7,6 +7,7 @@ digraph state_automaton { {node [shape = plaintext] "thread_context"}; "__init_thread_context" -> "thread_context"; "scheduling_context" [label = "scheduling_context"]; + "scheduling_context" -> "scheduling_context" [ label = "sched_set_state_runnable_signal" ]; "scheduling_context" -> "thread_context" [ label = "schedule_exit" ]; "thread_context" [label = "thread_context", color = green3]; "thread_context" -> "scheduling_context" [ label = "schedule_entry" ];
--
2.49.0