kernel/linux.git/tools/testing/selftests/sched_ext, branch v7.0.11

selftests/sched_ext: Add missing error check for exit__load()

2026-05-23T11:08:45+00:00

[ Upstream commit 1d02346fec8d13b05e54296ddc6ae29b7e1067df ] exit__load(skel) was called without checking its return value. Every other test in the suite wraps the load call with SCX_FAIL_IF(). Add the missing check to be consistent with the rest of the test suite. Fixes: a5db7817af78 ("sched_ext: Add selftests") Signed-off-by: David Carlier Signed-off-by: Tejun Heo Signed-off-by: Sasha Levin

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

sched_ext/selftests: Fix format specifier and buffer length in file_write_long()

2026-03-04T22:07:43+00:00

Use %ld (not %lu) for signed long, and pass the actual string length returned by sprintf() to write_text() instead of sizeof(buf). Signed-off-by: Cheng-Yang Chou Signed-off-by: Tejun Heo

selftests/sched_ext: Fix peek_dsq.bpf.c compile error for clang 17

2026-03-03T08:00:34+00:00

When compiling sched_ext selftests using clang 17.0.6, it raised compiler crash and build error: Error at line 68: Unsupport signed division for DAG: 0x55b2f9a60240: i64 = sdiv 0x55b2f9a609b0, Constant:i64<100>, peek_dsq.bpf.c:68:25 @[ peek_dsq.bpf.c:95:4 @[ peek_dsq.bpf.c:169:8 @[ peek _dsq.bpf.c:140:6 ] ] ]Please convert to unsigned div/mod After digging, it's not a compiler error, clang supported Signed division only when using -mcpu=v4, while we use -mcpu=v3 currently, the better way is to use unsigned div, see [1] for details. [1] https://github.com/llvm/llvm-project/issues/70433 Signed-off-by: Zhao Mengmeng Reviewed-by: Andrea Righi Signed-off-by: Tejun Heo

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: Remove duplicated unistd.h include in rt_stall.c

2026-02-23T17:45:39+00:00

The header is included twice in rt_stall.c. Remove the redundant inclusion to clean up the code. Signed-off-by: Cheng-Yang Chou Signed-off-by: Tejun Heo

selftests/sched_ext: Fix unused-result warning for read()

2026-02-23T17:45:10+00:00

The read() call in run_test() triggers a warn_unused_result compiler warning, which breaks the build under -Werror. Check the return value of read() and exit the child process on failure to satisfy the compiler and handle pipe read errors. Reviewed-by: Andrea Righi Signed-off-by: Cheng-Yang Chou Signed-off-by: Tejun Heo

selftests/sched_ext: Abort test loop on signal

2026-02-23T17:19:13+00:00

The runner sets exit_req on SIGINT/SIGTERM but ignores it during the main loop. This prevents users from cleanly interrupting a test run. Check exit_req each iteration to safely break out on exit signals. Signed-off-by: Cheng-Yang Chou Acked-by: Andrea Righi Signed-off-by: Tejun Heo

selftests/sched_ext: Fix rt_stall flaky failure

2026-02-13T19:09:39+00:00

The rt_stall test measures the runtime ratio between an EXT and an RT task pinned to the same CPU, verifying that the deadline server prevents RT tasks from starving SCHED_EXT tasks. It expects the EXT task to get at least 4% of CPU time. The test is flaky because sched_stress_test() calls sleep(RUN_TIME) immediately after fork(), without waiting for the RT child to complete its setup (set_affinity + set_sched). If the RT child experiences scheduling latency before completing setup, that delay eats into the measurement window: the RT child runs for less than RUN_TIME seconds, and the EXT task's measured ratio drops below the 4% threshold. For example, in the failing CI run [1]: EXT=0.140s RT=4.750s total=4.890s (expected ~5.0s) ratio=2.86% < 4% → FAIL The 110ms gap (5.0 - 4.89) corresponds to the RT child's setup time being counted inside the measurement window, during which fewer deadline server ticks fire for the EXT task. Fix by using pipes to synchronize: each child signals the parent after completing its setup, and the parent waits for both signals before starting sleep(RUN_TIME). This ensures the measurement window only counts time when both tasks are fully configured and competing. [1] https://github.com/kernel-patches/bpf/actions/runs/21961895809/job/63442490449 Fixes: be621a76341c ("selftests/sched_ext: Add test for sched_ext dl_server") Assisted-by: claude-opus-4-6-v1 Signed-off-by: Ihor Solodrai Reviewed-by: Andrea Righi Signed-off-by: Tejun Heo

Merge tag 'sched_ext-for-6.20' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext

2026-02-11T21:35:24+00:00

Pull sched_ext updates from Tejun Heo: - Move C example schedulers back from the external scx repo to tools/sched_ext as the authoritative source. scx_userland and scx_pair are returning while scx_sdt (BPF arena-based task data management) is new. These schedulers will be dropped from the external repo. - Improve error reporting by adding scx_bpf_error() calls when DSQ creation fails across all in-tree schedulers - Avoid redundant irq_work_queue() calls in destroy_dsq() by only queueing when llist_add() indicates an empty list - Fix flaky init_enable_count selftest by properly synchronizing pre-forked children using a pipe instead of sleep() * tag 'sched_ext-for-6.20' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext: selftests/sched_ext: Fix init_enable_count flakiness tools/sched_ext: Fix data header access during free in scx_sdt tools/sched_ext: Add error logging for dsq creation failures in remaining schedulers tools/sched_ext: add arena based scheduler tools/sched_ext: add scx_pair scheduler tools/sched_ext: add scx_userland scheduler sched_ext: Add error logging for dsq creation failures sched_ext: Avoid multiple irq_work_queue() calls in destroy_dsq()