Building the dequeue selftest with newer compilers (e.g., gcc 16)
triggers the following error:
dequeue.c:28:22: error: variable 'sum' set but not used
The 'volatile' qualifier prevents the writes from being optimized away,
but does not silence the unused variable 'sum' is indeed only written
and never read.
Consume 'sum' via an empty asm() with a register input constraint. This
forces the compiler to keep the accumulated value (preserving the CPU
stress loop) and avoiding the build error.
Fixes: 658ad2259b ("selftests/sched_ext: Add test to validate ops.dequeue() semantics")
Signed-off-by: Andrea Righi <arighi@nvidia.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Verify that the BPF verifier rejects a non-SCX struct_ops program
(tcp_congestion_ops) that attempts to call an SCX kfunc (scx_bpf_kick_cpu).
The test expects the load to fail with -EACCES from scx_kfunc_context_filter.
Signed-off-by: Cheng-Yang Chou <yphbchou0911@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
The error path after scx_bpf_create_dsq(real_dsq_id, ...) was reporting
test_dsq_id instead of real_dsq_id in the error message, which would
mislead debugging.
Signed-off-by: fangqiurong <fangqiurong@kylinos.cn>
Signed-off-by: Tejun Heo <tj@kernel.org>
Report an error for './runner foo' (positional arg instead of -t) and
for './runner -t foo' when the filter matches no tests. Previously both
cases produced no error output.
Pre-scan the test list before the main loop so the error is reported
immediately, avoiding spurious SKIP output from '-s' when no tests
match.
Signed-off-by: Cheng-Yang Chou <yphbchou0911@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Conflict in kernel/sched/ext.c init_sched_ext_class() between:
415cb193bb ("sched_ext: Fix SCX_KICK_WAIT deadlock by deferring wait
to balance callback")
which adds cpus_to_sync cpumask allocation, and:
84b1a0ea0b ("sched_ext: Implement scx_bpf_dsq_reenq() for user DSQs")
8c1b9453fd ("sched_ext: Convert deferred_reenq_locals from llist to
regular list")
which add deferred_reenq init code at the same location. Both are
independent additions. Include both.
Signed-off-by: Tejun Heo <tj@kernel.org>
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 <tj@kernel.org>
Reviewed-by: Christian Loehle <christian.loehle@arm.com>
Tested-by: Christian Loehle <christian.loehle@arm.com>
This reverts commit c50dcf5331.
The tests are superficial, likely AI-generated slop, and flaky. They
don't add actual value and just churn the selftests.
Signed-off-by: Tejun Heo <tj@kernel.org>
rt_stall tests the ext DL server which was introduced in commit
cd959a3562 ("sched_ext: Add a DL server for sched_ext tasks").
On older kernels that lack this feature, the test calls ksft_exit_fail()
internally which terminates the entire runner process, preventing
subsequent tests from running.
Add a guard in setup() that checks for the ext_server field in struct rq
via __COMPAT_struct_has_field() and returns SCX_TEST_SKIP if not present.
Also print the names of skipped tests in the results summary, mirroring
the existing behavior for failed tests.
Signed-off-by: Cheng-Yang Chou <yphbchou0911@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Add three selftests covering features introduced in v7.1:
- dsq_reenq: Verify scx_bpf_dsq_reenq() on user DSQs triggers
ops.enqueue() with SCX_ENQ_REENQ and SCX_TASK_REENQ_KFUNC in
p->scx.flags.
- enq_immed: Verify SCX_OPS_ALWAYS_ENQ_IMMED slow path where tasks
dispatched to a busy CPU's local DSQ are re-enqueued through
ops.enqueue() with SCX_TASK_REENQ_IMMED.
- consume_immed: Verify SCX_ENQ_IMMED via the consume path using
scx_bpf_dsq_move_to_local___v2() with explicit SCX_ENQ_IMMED.
All three tests skip gracefully on kernels that predate the required
features by checking availability via __COMPAT_has_ksym() /
__COMPAT_read_enum() before loading.
Signed-off-by: zhidao su <suzhidao@xiaomi.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
runner.c always returned 0 regardless of test results. The kselftest
framework (tools/testing/selftests/kselftest/runner.sh) invokes the runner
binary and treats a non-zero exit code as a test failure; with the old
code, failed sched_ext tests were silently hidden from the parent harness
even though individual "not ok" TAP lines were emitted.
Return 1 when at least one test failed, 0 when all tests passed or were
skipped.
Signed-off-by: zhidao su <suzhidao@xiaomi.com>
Acked-by: Andrea Righi <arighi@nvidia.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
When tests fail, the runner only printed the failure count, making
it hard to tell which tests failed without scrolling through output.
Track failed test names in an array and print them after the summary
so failures are immediately visible at the end of the run.
Signed-off-by: Cheng-Yang Chou <yphbchou0911@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
ops.cpu_acquire/release() are deprecated by commit a3f5d48222
("sched_ext: Allow scx_bpf_reenqueue_local() to be called from
anywhere") in favor of handling CPU preemption via the sched_switch
tracepoint.
In the maximal selftest, replace the cpu_acquire/release stubs with a
minimal sched_switch TP program. Attach all non-struct_ops programs
(including the new TP) via maximal__attach() after disabling auto-attach
for the maximal_ops struct_ops map, which is managed manually in run().
Apply the same fix to reload_loop, which also uses the maximal skeleton.
Signed-off-by: Cheng-Yang Chou <yphbchou0911@gmail.com>
Reviewed-by: Andrea Righi <arighi@nvidia.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Direct writes to p->scx.dsq_vtime are deprecated in favor of
scx_bpf_task_set_dsq_vtime(). Update scx_simple, scx_flatcg, and
select_cpu_vtime selftest to use the new kfunc with
scale_by_task_weight_inverse().
Signed-off-by: Cheng-Yang Chou <yphbchou0911@gmail.com>
Reviewed-by: Andrea Righi <arighi@nvidia.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Fix two mismatched closing comments in header include guards:
- util.h: closing comment says __SCX_TEST_H__ but the guard is
__SCX_TEST_UTIL_H__
- exit_test.h: closing comment has a spurious '#' character before
the guard name
Signed-off-by: Cheng-Yang Chou <yphbchou0911@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
After commit 860683763e ("sched_ext: Add enq_flags to
scx_bpf_dsq_move_to_local()") some of the kselftests are failing to
build:
exit.bpf.c:44:34: error: too few arguments provided to function-like macro invocation
44 | scx_bpf_dsq_move_to_local(DSQ_ID);
Update the kselftests adding the new argument to
scx_bpf_dsq_move_to_local().
Fixes: 860683763e ("sched_ext: Add enq_flags to scx_bpf_dsq_move_to_local()")
Signed-off-by: Andrea Righi <arighi@nvidia.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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: a5db7817af ("sched_ext: Add selftests")
Signed-off-by: David Carlier <devnexen@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Several demo schedulers and the selftest runner had usage strings
that omitted options which are actually supported:
- scx_central: add missing [-v]
- scx_pair: add missing [-v]
- scx_qmap: add missing [-S] and [-H]
- scx_userland: add missing [-v]
- scx_sdt: remove [-f] which no longer exists
- runner.c: add missing [-s], [-l], [-q]; drop [-h] which none of the
other sched_ext tools list in their usage lines
Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Cheng-Yang Chou <yphbchou0911@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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 <yphbchou0911@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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 <zhaomengmeng@kylinos.cn>
Reviewed-by: Andrea Righi <arighi@nvidia.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Similar to commit 835a507535 ("selftests/bpf: Add -fms-extensions to
bpf build flags") and commit 639f58a0f4 ("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 <zhaomengmeng@kylinos.cn>
Reviewed-by: Andrea Righi <arighi@nvidia.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Add a new kselftest to validate that the new ops.dequeue() semantics
work correctly for all task lifecycle scenarios, including the
distinction between terminal DSQs (where BPF scheduler is done with the
task), user DSQs (where BPF scheduler manages the task lifecycle) and
BPF data structures, regardless of which event performs the dispatch.
The test validates the following scenarios:
- From ops.select_cpu():
- scenario 0 (local DSQ): tasks dispatched to the local DSQ bypass
the BPF scheduler entirely; they never enter BPF custody, so
ops.dequeue() is not called,
- scenario 1 (global DSQ): tasks dispatched to SCX_DSQ_GLOBAL also
bypass the BPF scheduler, like the local DSQ; ops.dequeue() is
not called,
- scenario 2 (user DSQ): tasks dispatched to user DSQs from
ops.select_cpu(): tasks enter BPF scheduler's custody with full
enqueue/dequeue lifecycle tracking and state machine validation,
expects 1:1 enqueue/dequeue pairing,
- From ops.enqueue():
- scenario 3 (local DSQ): same behavior as scenario 0,
- scenario 4 (global DSQ): same behavior as scenario 1,
- scenario 5 (user DSQ): same behavior as scenario 2,
- scenario 6 (BPF internal queue): tasks are stored in a BPF queue
from ops.enqueue() and consumed from ops.dispatch(); similarly to
scenario 5, tasks enter BPF scheduler's custody with full
lifecycle tracking and 1:1 enqueue/dequeue validation.
This verifies that:
- terminal DSQ dispatch (local, global) don't trigger ops.dequeue(),
- tasks dispatched to user DSQs, either from ops.select_cpu() or
ops.enqueue(), enter BPF scheduler's custody and have exact 1:1
enqueue/dequeue pairing,
- tasks stored to internal BPF data structures from ops.enqueue() enter
BPF scheduler's custody and have exact 1:1 enqueue/dequeue pairing,
- dispatch dequeues have no flags (normal workflow),
- property change dequeues have the %SCX_DEQ_SCHED_CHANGE flag set,
- no duplicate enqueues or invalid state transitions are happening.
Cc: Tejun Heo <tj@kernel.org>
Cc: Emil Tsalapatis <emil@etsalapatis.com>
Cc: Kuba Piecuch <jpiecuch@google.com>
Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com>
Signed-off-by: Andrea Righi <arighi@nvidia.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
The header <unistd.h> is included twice in rt_stall.c. Remove the
redundant inclusion to clean up the code.
Signed-off-by: Cheng-Yang Chou <yphbchou0911@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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 <arighi@nvidia.com>
Signed-off-by: Cheng-Yang Chou <yphbchou0911@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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 <yphbchou0911@gmail.com>
Acked-by: Andrea Righi <arighi@nvidia.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Andrea RighiandTejun Heo
Cheng-Yang ChouandTejun Heo
fangqiurongandTejun Heo
zhidao suandTejun Heo
David CarlierandTejun Heo
Zhao MengmengandTejun Heo