kernel/linux.git/tools/testing/selftests/sched_ext/Makefile, branch linux-7.0.y

selftests/sched_ext: Add cyclic SCX_KICK_WAIT stress test

2026-03-30T18:37:55+00:00

Add a test that creates a 3-CPU kick_wait cycle (A->B->C->A). A BPF scheduler kicks the next CPU in the ring with SCX_KICK_WAIT on every enqueue while userspace workers generate continuous scheduling churn via sched_yield(). Without the preceding fix, this hangs the machine within seconds. Signed-off-by: Tejun Heo Reviewed-by: Christian Loehle Tested-by: Christian Loehle

selftests/sched_ext: Add -fms-extensions to bpf build flags

2026-03-03T08:00:31+00:00

Similar to commit 835a50753579 ("selftests/bpf: Add -fms-extensions to bpf build flags") and commit 639f58a0f480 ("bpftool: Fix build warnings due to MS extensions") Fix "declaration does not declare anything" warning by using -fms-extensions and -Wno-microsoft-anon-tag flags to build bpf programs that #include "vmlinux.h" Signed-off-by: Zhao Mengmeng Reviewed-by: Andrea Righi Signed-off-by: Tejun Heo

selftests/sched_ext: Add test for DL server total_bw consistency

2026-02-03T11:04:18+00:00

Add a new kselftest to verify that the total_bw value in /sys/kernel/debug/sched/debug remains consistent across all CPUs under different sched_ext BPF program states: 1. Before a BPF scheduler is loaded 2. While a BPF scheduler is loaded and active 3. After a BPF scheduler is unloaded The test runs CPU stress threads to ensure DL server bandwidth values stabilize before checking consistency. This helps catch potential issues with DL server bandwidth accounting during sched_ext transitions. Co-developed-by: Andrea Righi Signed-off-by: Andrea Righi Signed-off-by: Joel Fernandes Signed-off-by: Peter Zijlstra (Intel) Tested-by: Christian Loehle Link: https://patch.msgid.link/20260126100050.3854740-8-arighi@nvidia.com

selftests/sched_ext: Add test for sched_ext dl_server

2026-02-03T11:04:18+00:00

Add a selftest to validate the correct behavior of the deadline server for the ext_sched_class. Co-developed-by: Joel Fernandes Signed-off-by: Joel Fernandes Signed-off-by: Andrea Righi Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Emil Tsalapatis Tested-by: Christian Loehle Link: https://patch.msgid.link/20260126100050.3854740-7-arighi@nvidia.com

sched_ext: Add a selftest for scx_bpf_dsq_peek

2025-10-15T16:46:36+00:00

This commit adds two tests. The first is the most basic unit test: make sure an empty queue peeks as empty, and when we put one element in the queue, make sure peek returns that element. However, even this simple test is a little complicated by the different behavior of scx_bpf_dsq_insert in different calling contexts: - insert is for direct dispatch in enqueue - insert is delayed when called from select_cpu In this case we split the insert and the peek that verifies the result between enqueue/dispatch. Note: An alternative would be to call `scx_bpf_dsq_move_to_local` on an empty queue, which in turn calls `flush_dispatch_buf`, in order to flush the buffered insert. Unfortunately, this is not viable within the enqueue path, as it attempts a voluntary context switch within an RCU read-side critical section. The second test is a stress test that performs many peeks on all DSQs and records the observed tasks. Signed-off-by: Ryan Newton Reviewed-by: Christian Loehle Signed-off-by: Tejun Heo

selftests/sched_ext: Update test enq_select_cpu_fails

2025-05-21T17:35:58+00:00

With commit 08699d20467b6 ("sched_ext: idle: Consolidate default idle CPU selection kfuncs") allowing scx_bpf_select_cpu_dfl() to be invoked from multiple contexts, update the test to validate that the kfunc behaves correctly when used from ops.enqueue() and via BPF test_run. Additionally, rename the test to enq_select_cpu, dropping "fails" from the name, as the logic has now been inverted. Signed-off-by: Andrea Righi Signed-off-by: Tejun Heo

selftests/sched_ext: Add test for scx_bpf_select_cpu_and()

2025-04-07T17:13:52+00:00

Add a selftest to validate the behavior of the built-in idle CPU selection policy applied to a subset of allowed CPUs, using scx_bpf_select_cpu_and(). Signed-off-by: Andrea Righi Signed-off-by: Tejun Heo

selftests/sched_ext: Add NUMA-aware scheduler test

2025-02-26T18:49:02+00:00

Add a selftest to validate the behavior of the NUMA-aware scheduler functionalities, including idle CPU selection within nodes, per-node DSQs and CPU to node mapping. Signed-off-by: Andrea Righi Signed-off-by: Tejun Heo

selftests/sched_ext: add order-only dependency of runner.o on BPFOBJ

2024-10-23T18:56:32+00:00

The runner.o may start building before libbpf headers are installed, and as a result build fails. This happened a couple of times on libbpf/ci test jobs: * https://github.com/libbpf/ci/actions/runs/11447667257/job/31849533100 * https://github.com/theihor/libbpf-ci/actions/runs/11445162764/job/31841649552 Headers are installed in a recipe for $(BPFOBJ) target, and adding an order-only dependency should ensure this doesn't happen. Signed-off-by: Ihor Solodrai Signed-off-by: Tejun Heo

selftests: sched_ext: Add sched_ext as proper selftest target

2024-10-09T16:42:51+00:00

The sched_ext selftests is missing proper cross-compilation support, a proper target entry, and out-of-tree build support. When building the kselftest suite, e.g.: make ARCH=riscv CROSS_COMPILE=riscv64-linux-gnu- \ TARGETS=sched_ext SKIP_TARGETS="" O=/output/foo \ -C tools/testing/selftests install or: make ARCH=arm64 LLVM=1 TARGETS=sched_ext SKIP_TARGETS="" \ O=/output/foo -C tools/testing/selftests install The expectation is that the sched_ext is included, cross-built, the correct toolchain is picked up, and placed into /output/foo. In contrast to the BPF selftests, the sched_ext suite does not use bpftool at test run-time, so it is sufficient to build bpftool for the build host only. Add ARCH, CROSS_COMPILE, OUTPUT, and TARGETS support to the sched_ext selftest. Also, remove some variables that were unused by the Makefile. Signed-off-by: Björn Töpel Reviewed-by: Shuah Khan Acked-by: David Vernet Tested-by: Mark Brown Reviewed-by: Mark Brown Signed-off-by: Tejun Heo