linux.git/tools/testing/selftests/sched_ext/Makefile, branch master

selftests/sched_ext: Add non_scx_kfunc_deny test

2026-04-20T17:57:29+00:00

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 
Signed-off-by: Tejun Heo

Merge branch 'for-7.0-fixes' into for-7.1

2026-03-30T19:02:05+00:00

Conflict in kernel/sched/ext.c init_sched_ext_class() between:

  415cb193bb97 ("sched_ext: Fix SCX_KICK_WAIT deadlock by deferring wait
  to balance callback")

which adds cpus_to_sync cpumask allocation, and:

  84b1a0ea0b7c ("sched_ext: Implement scx_bpf_dsq_reenq() for user DSQs")
  8c1b9453fde6 ("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

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

Revert "selftests/sched_ext: Add tests for SCX_ENQ_IMMED and scx_bpf_dsq_reenq()"

2026-03-27T00:45:37+00:00

This reverts commit c50dcf533149.

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

selftests/sched_ext: Add tests for SCX_ENQ_IMMED and scx_bpf_dsq_reenq()

2026-03-23T00:29:42+00:00

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 
Signed-off-by: Tejun Heo

Merge branch 'for-7.0-fixes' into for-7.1

2026-03-06T17:46:32+00:00

To prepare for hierarchical scheduling patchset which will cause multiple
conflicts otherwise.

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: Add test to validate ops.dequeue() semantics

2026-02-23T20:01:38+00:00

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 
Cc: Emil Tsalapatis 
Cc: Kuba Piecuch 
Reviewed-by: Daniel Jordan 
Signed-off-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