fix(scheduler): solve inter-scheduler priority inversion by atsushi421 · Pull Request #655 · tier4/awkernel

atsushi421 · 2025-09-24T03:59:12Z

Description

This solves the inter-scheduler priority inversion. This also changes the promela model and verifies it.

How was this PR tested?

Model checking. Please see README.md for detail.
Test application (test_multi_prioritized_scheduler). The log is as follows.

[         3804 DEBUG] /home/atsushi/awkernel/applications/tests/test_multi_prioritized_scheduler/src/lib.rs:22: low priority task 1 started. sched_type = PrioritizedRR(0)
[         3811 DEBUG] /home/atsushi/awkernel/applications/tests/test_multi_prioritized_scheduler/src/lib.rs:22: low priority task 2 started. sched_type = GEDF(1000)
[         3820 DEBUG] /home/atsushi/awkernel/applications/tests/test_multi_prioritized_scheduler/src/lib.rs:22: low priority task 3 started. sched_type = PrioritizedFIFO(0)
[         3836 DEBUG] /home/atsushi/awkernel/applications/tests/test_multi_prioritized_scheduler/src/lib.rs:22: low priority task 5 started. sched_type = GEDF(1000)
[         3852 DEBUG] /home/atsushi/awkernel/applications/tests/test_multi_prioritized_scheduler/src/lib.rs:22: low priority task 6 started. sched_type = PrioritizedFIFO(0)
[         3852 DEBUG] /home/atsushi/awkernel/applications/tests/test_multi_prioritized_scheduler/src/lib.rs:22: low priority task 8 started. sched_type = GEDF(1000)
[         3853 DEBUG] /home/atsushi/awkernel/applications/tests/test_multi_prioritized_scheduler/src/lib.rs:22: low priority task 4 started. sched_type = PrioritizedRR(0)
[         3854 DEBUG] /home/atsushi/awkernel/applications/tests/test_multi_prioritized_scheduler/src/lib.rs:22: low priority task 7 started. sched_type = PrioritizedRR(0)
[         3885 DEBUG] /home/atsushi/awkernel/applications/tests/test_multi_prioritized_scheduler/src/lib.rs:22: low priority task 9 started. sched_type = PrioritizedFIFO(0)
[         3916 DEBUG] /home/atsushi/awkernel/applications/tests/test_multi_prioritized_scheduler/src/lib.rs:22: low priority task 11 started. sched_type = GEDF(1000)
[         4044 DEBUG] /home/atsushi/awkernel/applications/tests/test_multi_prioritized_scheduler/src/lib.rs:22: low priority task 12 started. sched_type = PrioritizedFIFO(0)
[         4124 DEBUG] /home/atsushi/awkernel/applications/tests/test_multi_prioritized_scheduler/src/lib.rs:22: low priority task 14 started. sched_type = GEDF(1000)
[         4188 DEBUG] /home/atsushi/awkernel/applications/tests/test_multi_prioritized_scheduler/src/lib.rs:22: low priority task 15 started. sched_type = PrioritizedFIFO(0)
[         4620 DEBUG] /home/atsushi/awkernel/applications/tests/test_multi_prioritized_scheduler/src/lib.rs:43: high priority task 2 started. sched_type = GEDF(500)
[         4636 DEBUG] /home/atsushi/awkernel/applications/tests/test_multi_prioritized_scheduler/src/lib.rs:43: high priority task 3 started. sched_type = PrioritizedFIFO(1)
[         4732 DEBUG] /home/atsushi/awkernel/applications/tests/test_multi_prioritized_scheduler/src/lib.rs:45: high priority task 2 finished. sched_type = GEDF(500)
[         4764 DEBUG] /home/atsushi/awkernel/applications/tests/test_multi_prioritized_scheduler/src/lib.rs:43: high priority task 5 started. sched_type = GEDF(500)
[         4764 DEBUG] /home/atsushi/awkernel/applications/tests/test_multi_prioritized_scheduler/src/lib.rs:45: high priority task 3 finished. sched_type = PrioritizedFIFO(1)
[         4812 DEBUG] /home/atsushi/awkernel/applications/tests/test_multi_prioritized_scheduler/src/lib.rs:43: high priority task 6 started. sched_type = PrioritizedFIFO(1)
[         4892 DEBUG] /home/atsushi/awkernel/applications/tests/test_multi_prioritized_scheduler/src/lib.rs:24: low priority task 8 finished. sched_type = GEDF(1000)
[         4908 DEBUG] /home/atsushi/awkernel/applications/tests/test_multi_prioritized_scheduler/src/lib.rs:24: low priority task 5 finished. sched_type = GEDF(1000)
[         4924 DEBUG] /home/atsushi/awkernel/applications/tests/test_multi_prioritized_scheduler/src/lib.rs:45: high priority task 5 finished. sched_type = GEDF(500)
[         4924 DEBUG] /home/atsushi/awkernel/applications/tests/test_multi_prioritized_scheduler/src/lib.rs:24: low priority task 6 finished. sched_type = PrioritizedFIFO(0)
[         4940 DEBUG] /home/atsushi/awkernel/applications/tests/test_multi_prioritized_scheduler/src/lib.rs:24: low priority task 3 finished. sched_type = PrioritizedFIFO(0)
[         4940 DEBUG] /home/atsushi/awkernel/applications/tests/test_multi_prioritized_scheduler/src/lib.rs:43: high priority task 1 started. sched_type = PrioritizedRR(1)
[         4972 DEBUG] /home/atsushi/awkernel/applications/tests/test_multi_prioritized_scheduler/src/lib.rs:43: high priority task 8 started. sched_type = GEDF(500)
[         4972 DEBUG] /home/atsushi/awkernel/applications/tests/test_multi_prioritized_scheduler/src/lib.rs:24: low priority task 11 finished. sched_type = GEDF(1000)
[         4988 DEBUG] /home/atsushi/awkernel/applications/tests/test_multi_prioritized_scheduler/src/lib.rs:45: high priority task 6 finished. sched_type = PrioritizedFIFO(1)
[         5004 DEBUG] /home/atsushi/awkernel/applications/tests/test_multi_prioritized_scheduler/src/lib.rs:43: high priority task 7 started. sched_type = PrioritizedRR(1)
[         5004 DEBUG] /home/atsushi/awkernel/applications/tests/test_multi_prioritized_scheduler/src/lib.rs:24: low priority task 2 finished. sched_type = GEDF(1000)
[         5004 DEBUG] /home/atsushi/awkernel/applications/tests/test_multi_prioritized_scheduler/src/lib.rs:43: high priority task 9 started. sched_type = PrioritizedFIFO(1)
[         5004 DEBUG] /home/atsushi/awkernel/applications/tests/test_multi_prioritized_scheduler/src/lib.rs:24: low priority task 9 finished. sched_type = PrioritizedFIFO(0)
[         5004 DEBUG] /home/atsushi/awkernel/applications/tests/test_multi_prioritized_scheduler/src/lib.rs:43: high priority task 4 started. sched_type = PrioritizedRR(1)
[         5005 DEBUG] /home/atsushi/awkernel/applications/tests/test_multi_prioritized_scheduler/src/lib.rs:43: high priority task 10 started. sched_type = PrioritizedRR(1)
[         5036 DEBUG] /home/atsushi/awkernel/applications/tests/test_multi_prioritized_scheduler/src/lib.rs:43: high priority task 11 started. sched_type = GEDF(500)
[         5052 DEBUG] /home/atsushi/awkernel/applications/tests/test_multi_prioritized_scheduler/src/lib.rs:43: high priority task 12 started. sched_type = PrioritizedFIFO(1)
[         5100 DEBUG] /home/atsushi/awkernel/applications/tests/test_multi_prioritized_scheduler/src/lib.rs:43: high priority task 13 started. sched_type = PrioritizedRR(1)
[         5100 DEBUG] /home/atsushi/awkernel/applications/tests/test_multi_prioritized_scheduler/src/lib.rs:43: high priority task 14 started. sched_type = GEDF(500)
[         5100 DEBUG] /home/atsushi/awkernel/applications/tests/test_multi_prioritized_scheduler/src/lib.rs:45: high priority task 8 finished. sched_type = GEDF(500)
[         5132 DEBUG] /home/atsushi/awkernel/applications/tests/test_multi_prioritized_scheduler/src/lib.rs:45: high priority task 1 finished. sched_type = PrioritizedRR(1)
[         5132 DEBUG] /home/atsushi/awkernel/applications/tests/test_multi_prioritized_scheduler/src/lib.rs:45: high priority task 9 finished. sched_type = PrioritizedFIFO(1)
[         5132 DEBUG] /home/atsushi/awkernel/applications/tests/test_multi_prioritized_scheduler/src/lib.rs:24: low priority task 14 finished. sched_type = GEDF(1000)
[         5133 DEBUG] /home/atsushi/awkernel/applications/tests/test_multi_prioritized_scheduler/src/lib.rs:43: high priority task 15 started. sched_type = PrioritizedFIFO(1)
[         5148 DEBUG] /home/atsushi/awkernel/applications/tests/test_multi_prioritized_scheduler/src/lib.rs:45: high priority task 10 finished. sched_type = PrioritizedRR(1)
[         5180 DEBUG] /home/atsushi/awkernel/applications/tests/test_multi_prioritized_scheduler/src/lib.rs:45: high priority task 12 finished. sched_type = PrioritizedFIFO(1)
[         5196 DEBUG] /home/atsushi/awkernel/applications/tests/test_multi_prioritized_scheduler/src/lib.rs:24: low priority task 15 finished. sched_type = PrioritizedFIFO(0)
[         5212 DEBUG] /home/atsushi/awkernel/applications/tests/test_multi_prioritized_scheduler/src/lib.rs:45: high priority task 11 finished. sched_type = GEDF(500)
[         5212 DEBUG] /home/atsushi/awkernel/applications/tests/test_multi_prioritized_scheduler/src/lib.rs:24: low priority task 4 finished. sched_type = PrioritizedRR(0)
[         5212 DEBUG] /home/atsushi/awkernel/applications/tests/test_multi_prioritized_scheduler/src/lib.rs:24: low priority task 12 finished. sched_type = PrioritizedFIFO(0)
[         5212 DEBUG] /home/atsushi/awkernel/applications/tests/test_multi_prioritized_scheduler/src/lib.rs:24: low priority task 7 finished. sched_type = PrioritizedRR(0)
[         5292 DEBUG] /home/atsushi/awkernel/applications/tests/test_multi_prioritized_scheduler/src/lib.rs:45: high priority task 4 finished. sched_type = PrioritizedRR(1)
[         5292 DEBUG] /home/atsushi/awkernel/applications/tests/test_multi_prioritized_scheduler/src/lib.rs:45: high priority task 13 finished. sched_type = PrioritizedRR(1)
[         5292 DEBUG] /home/atsushi/awkernel/applications/tests/test_multi_prioritized_scheduler/src/lib.rs:45: high priority task 15 finished. sched_type = PrioritizedFIFO(1)
[         5292 DEBUG] /home/atsushi/awkernel/applications/tests/test_multi_prioritized_scheduler/src/lib.rs:22: low priority task 13 started. sched_type = PrioritizedRR(0)
[         5292 DEBUG] /home/atsushi/awkernel/applications/tests/test_multi_prioritized_scheduler/src/lib.rs:24: low priority task 1 finished. sched_type = PrioritizedRR(0)
[         5293 DEBUG] /home/atsushi/awkernel/applications/tests/test_multi_prioritized_scheduler/src/lib.rs:45: high priority task 14 finished. sched_type = GEDF(500)
[         5293 DEBUG] /home/atsushi/awkernel/applications/tests/test_multi_prioritized_scheduler/src/lib.rs:22: low priority task 10 started. sched_type = PrioritizedRR(0)
[         5308 DEBUG] /home/atsushi/awkernel/applications/tests/test_multi_prioritized_scheduler/src/lib.rs:45: high priority task 7 finished. sched_type = PrioritizedRR(1)
[         6412 DEBUG] /home/atsushi/awkernel/applications/tests/test_multi_prioritized_scheduler/src/lib.rs:24: low priority task 13 finished. sched_type = PrioritizedRR(0)
[         6413 DEBUG] /home/atsushi/awkernel/applications/tests/test_multi_prioritized_scheduler/src/lib.rs:24: low priority task 10 finished. sched_type = PrioritizedRR(0)

Notes for reviewers

The Mutex for each scheduler's data is unnecessary for now, such as

pub static SCHEDULER: PrioritizedFIFOScheduler = PrioritizedFIFOScheduler {
    data: Mutex::new(None),  // <- this
    priority: get_priority(SchedulerType::PrioritizedFIFO(0)),
};

However, RefCell cannot be used for a field in a static object. Therefore, it remains. I would appreciate your comments on this if you have a better idea.

Signed-off-by: atsushi421 <atsushi.yano.2@tier4.jp>

* test: for develop #1 Signed-off-by: nokosaaan <nishimura.r.019@ms.saitama-u.ac.jp> * test: for develop #2 Signed-off-by: nokosaaan <nishimura.r.019@ms.saitama-u.ac.jp> * test: whether source_nodes or others & modify DAG struct #3 Signed-off-by: nokosaaan <nishimura.r.019@ms.saitama-u.ac.jp> * test: add else process for initial period #4 Signed-off-by: nokosaaan <nishimura.r.019@ms.saitama-u.ac.jp> * test: absolute deadline setting #5 Signed-off-by: nokosaaan <nishimura.r.019@ms.saitama-u.ac.jp> * fix: absolute deadline setting #6 Signed-off-by: nokosaaan <nishimura.r.019@ms.saitama-u.ac.jp> * fix absolute deadline #7 Signed-off-by: nokosaaan <nishimura.r.019@ms.saitama-u.ac.jp> * test: change gedf.rs #8 Signed-off-by: nokosaaan <nishimura.r.019@ms.saitama-u.ac.jp> * test: change gedf.rs #9 Signed-off-by: nokosaaan <nishimura.r.019@ms.saitama-u.ac.jp> * fix: delete unnecessary code Signed-off-by: nokosaaan <nishimura.r.019@ms.saitama-u.ac.jp> * fix: modify get_node_info and etc Signed-off-by: nokosaaan <nishimura.r.019@ms.saitama-u.ac.jp> * fix: change function name Signed-off-by: nokosaaan <nishimura.r.019@ms.saitama-u.ac.jp> * fix: organizing comments & modify else handling Signed-off-by: nokosaaan <nishimura.r.019@ms.saitama-u.ac.jp> * fix: remove unused methods Signed-off-by: nokosaaan <nishimura.r.019@ms.saitama-u.ac.jp> * fix: change PRIORITY_LIST & change dag.rs Signed-off-by: nokosaaan <nishimura.r.019@ms.saitama-u.ac.jp> * fix: change gedf.rs & task.rs Signed-off-by: nokosaaan <nishimura.r.019@ms.saitama-u.ac.jp> * fix: avoid deadlock for GEDFNoArg Signed-off-by: nokosaaan <nishimura.r.019@ms.saitama-u.ac.jp> * fix: change spawn logic Signed-off-by: nokosaaan <nishimura.r.019@ms.saitama-u.ac.jp> * fix: delete GEDFNoArg Signed-off-by: nokosaaan <nishimura.r.019@ms.saitama-u.ac.jp> * fix: check cargo fmt Signed-off-by: nokosaaan <nishimura.r.019@ms.saitama-u.ac.jp> * fix: adjusting the number of arguments Signed-off-by: nokosaaan <nishimura.r.019@ms.saitama-u.ac.jp> * fix: check cargo fmt 2 Signed-off-by: nokosaaan <nishimura.r.019@ms.saitama-u.ac.jp> * fix: improper variable usage in panic! macros Signed-off-by: nokosaaan <nishimura.r.019@ms.saitama-u.ac.jp> * fix: check doctest Signed-off-by: nokosaaan <nishimura.r.019@ms.saitama-u.ac.jp> * fix: check doctest 2 Signed-off-by: nokosaaan <nishimura.r.019@ms.saitama-u.ac.jp> * fix: check doctest 3 Signed-off-by: nokosaaan <nishimura.r.019@ms.saitama-u.ac.jp> * fix: check doctest 4 Signed-off-by: nokosaaan <nishimura.r.019@ms.saitama-u.ac.jp> * fix: check doctest 5 Signed-off-by: nokosaaan <nishimura.r.019@ms.saitama-u.ac.jp> * fix: check doctest 6 Signed-off-by: nokosaaan <nishimura.r.019@ms.saitama-u.ac.jp> * fix: check doctest 7 Signed-off-by: nokosaaan <nishimura.r.019@ms.saitama-u.ac.jp> * fix: check doctest 8 Signed-off-by: nokosaaan <nishimura.r.019@ms.saitama-u.ac.jp> * fix: check cargo fmt 3 Signed-off-by: nokosaaan <nishimura.r.019@ms.saitama-u.ac.jp> * fix: check doctest 9 Signed-off-by: nokosaaan <nishimura.r.019@ms.saitama-u.ac.jp> * fix: check doctest 10 Signed-off-by: nokosaaan <nishimura.r.019@ms.saitama-u.ac.jp> * fix: check doctest 11 Signed-off-by: nokosaaan <nishimura.r.019@ms.saitama-u.ac.jp> * fix: fix unnecessary imports Signed-off-by: nokosaaan <nishimura.r.019@ms.saitama-u.ac.jp> * fix: reset the LOG_ENABLE flag to its original state Signed-off-by: nokosaaan <nishimura.r.019@ms.saitama-u.ac.jp> * fix: delete unnecessary functions Signed-off-by: nokosaaan <nishimura.r.019@ms.saitama-u.ac.jp> * fix: delete unnecessary functions 2 Signed-off-by: nokosaaan <nishimura.r.019@ms.saitama-u.ac.jp> * fix: delete unnecessary functions 3 Signed-off-by: nokosaaan <nishimura.r.019@ms.saitama-u.ac.jp> * fix: implement gedf Signed-off-by: nokosaaan <nishimura.r.019@ms.saitama-u.ac.jp> * fix: check cargo fmt 4 Signed-off-by: nokosaaan <nishimura.r.019@ms.saitama-u.ac.jp> * fix: refactored the nested sections using helper functions Signed-off-by: nokosaaan <nishimura.r.019@ms.saitama-u.ac.jp> * fix: reduced nested structure using early return Signed-off-by: nokosaaan <nishimura.r.019@ms.saitama-u.ac.jp> * fix: adding a function and code optimization Signed-off-by: nokosaaan <nishimura.r.019@ms.saitama-u.ac.jp> * fix: check cargo fmt 5 Signed-off-by: nokosaaan <nishimura.r.019@ms.saitama-u.ac.jp> * fix: add a comment in dag.rs Signed-off-by: nokosaaan <nishimura.r.019@ms.saitama-u.ac.jp> * fix: format! error Signed-off-by: nokosaaan <nishimura.r.019@ms.saitama-u.ac.jp> * fix: To resolve the build error, I used unwrap_or_else instead of expect. Signed-off-by: nokosaaan <nishimura.r.019@ms.saitama-u.ac.jp> * fix: delete unnecessary import Signed-off-by: nokosaaan <nishimura.r.019@ms.saitama-u.ac.jp> * fix: delete semicolon Signed-off-by: nokosaaan <nishimura.r.019@ms.saitama-u.ac.jp> * fix: panic! 2 Signed-off-by: nokosaaan <nishimura.r.019@ms.saitama-u.ac.jp> * fix: unify the name index to id Signed-off-by: nokosaaan <nishimura.r.019@ms.saitama-u.ac.jp> * fix: consolidated the duplicate processing and add a comment Signed-off-by: nokosaaan <nishimura.r.019@ms.saitama-u.ac.jp> * fix: solve let binding Signed-off-by: nokosaaan <nishimura.r.019@ms.saitama-u.ac.jp> --------- Signed-off-by: nokosaaan <nishimura.r.019@ms.saitama-u.ac.jp>

fix(scheduler): solve inter-scheduler priority inversion

4fca63b

Signed-off-by: atsushi421 <atsushi.yano.2@tier4.jp>

github-actions bot assigned atsushi421 Sep 24, 2025

atsushi421 and others added 5 commits September 24, 2025 14:00

fix: clippy

45da902

fix: clippy

5b53abd

fix: change mutex range

a536ecf

docs: update README

80468f8

Merge branch 'main' into solve_inter_scheduler_priority_inversion

9928ea6

atsushi421 marked this pull request as ready for review September 24, 2025 20:15

atsushi421 requested a review from ytakano September 24, 2025 23:59

nokosaaan and others added 2 commits September 26, 2025 17:45

Merge branch 'main' into solve_inter_scheduler_priority_inversion

6fe24f9

ytakano approved these changes Oct 3, 2025

View reviewed changes

ytakano merged commit b4f90de into main Oct 3, 2025
1 check passed

ytakano deleted the solve_inter_scheduler_priority_inversion branch October 3, 2025 06:04

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fix(scheduler): solve inter-scheduler priority inversion#655

fix(scheduler): solve inter-scheduler priority inversion#655
ytakano merged 8 commits intomainfrom
solve_inter_scheduler_priority_inversion

atsushi421 commented Sep 24, 2025 •

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atsushi421 commented Sep 24, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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atsushi421 commented Sep 24, 2025 •

edited

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