linux/tools/testing/selftests/sched_ext, branch for-next

sched_ext: Fix dsq_local_on selftest

2024-12-25T00:09:50Z

The dsp_local_on selftest expects the scheduler to fail by trying to schedule an e.g. CPU-affine task to the wrong CPU. However, this isn't guaranteed to happen in the 1 second window that the test is running. Besides, it's odd to have this particular exception path tested when there are no other tests that verify that the interface is working at all - e.g. the test would pass if dsp_local_on interface is completely broken and fails on any attempt. Flip the test so that it verifies that the feature works. While at it, fix a typo in the info message. Signed-off-by: Tejun Heo Reported-by: Ihor Solodrai Link: http://lkml.kernel.org/r/Z1n9v7Z6iNJ-wKmq@slm.duckdns.org Signed-off-by: Tejun Heo

scx: Fix maximal BPF selftest prog

2024-12-11T06:30:50Z

maximal.bpf.c is still dispatching to and consuming from SCX_DSQ_GLOBAL. Let's have it use its own DSQ to avoid any runtime errors. Signed-off-by: David Vernet Tested-by: Andrea Righi Signed-off-by: Tejun Heo

selftests/sched_ext: fix build after renames in sched_ext API

2024-12-04T19:46:39Z

The selftests are falining to build on current tip of bpf-next and sched_ext [1]. This has broken BPF CI [2] after merge from upstream. Use appropriate function names in the selftests according to the recent changes in the sched_ext API [3]. [1] https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git/commit/?id=fc39fb56917bb3cb53e99560ca3612a84456ada2 [2] https://github.com/kernel-patches/bpf/actions/runs/11959327258/job/33340923745 [3] https://lore.kernel.org/all/20241109194853.580310-1-tj@kernel.org/ Signed-off-by: Ihor Solodrai Acked-by: Andrea Righi Acked-by: David Vernet Signed-off-by: Tejun Heo

sched_ext: Fix enq_last_no_enq_fails selftest

2024-10-25T22:20:29Z

cc9877fb7677 ("sched_ext: Improve error reporting during loading") changed how load failures are reported so that more error context can be communicated. This breaks the enq_last_no_enq_fails test as attach no longer fails. The scheduler is guaranteed to be ejected on attach completion with full error information. Update enq_last_no_enq_fails so that it checks that the scheduler is ejected using ops.exit(). Signed-off-by: Tejun Heo Reported-by: Vishal Chourasia Link: http://lkml.kernel.org/r/Zxknp7RAVNjmdJSc@linux.ibm.com Fixes: cc9877fb7677 ("sched_ext: Improve error reporting during loading")

scx: Fix exit selftest to use custom DSQ

2024-10-25T17:03:36Z

In commit 63fb3ec80516 ("sched_ext: Allow only user DSQs for scx_bpf_consume(), scx_bpf_dsq_nr_queued() and bpf_iter_scx_dsq_new()"), we updated the consume path to only accept user DSQs, thus making it invalid to consume SCX_DSQ_GLOBAL. This selftest was doing that, so let's create a custom DSQ and use that instead. The test now passes: [root@virtme-ng sched_ext]# ./runner -t exit ===== START ===== TEST: exit DESCRIPTION: Verify we can cleanly exit a scheduler in multiple places OUTPUT: [ 12.387229] sched_ext: BPF scheduler "exit" enabled [ 12.406064] sched_ext: BPF scheduler "exit" disabled (unregistered from BPF) [ 12.453325] sched_ext: BPF scheduler "exit" enabled [ 12.474064] sched_ext: BPF scheduler "exit" disabled (unregistered from BPF) [ 12.515241] sched_ext: BPF scheduler "exit" enabled [ 12.532064] sched_ext: BPF scheduler "exit" disabled (unregistered from BPF) [ 12.592063] sched_ext: BPF scheduler "exit" disabled (unregistered from BPF) [ 12.654063] sched_ext: BPF scheduler "exit" disabled (unregistered from BPF) [ 12.715062] sched_ext: BPF scheduler "exit" disabled (unregistered from BPF) ok 1 exit # ===== END ===== Signed-off-by: David Vernet Signed-off-by: Tejun Heo

sched_ext: Fix function pointer type mismatches in BPF selftests

2024-10-24T16:56:17Z

Fix incompatible function pointer type warnings in sched_ext BPF selftests by explicitly casting the function pointers when initializing struct_ops. This addresses multiple -Wincompatible-function-pointer-types warnings from the clang compiler where function signatures didn't match exactly. The void * cast ensures the compiler accepts the function pointer assignment despite minor type differences in the parameters. Signed-off-by: Vishal Chourasia Signed-off-by: Tejun Heo

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

2024-10-23T18:56:32Z

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

2024-10-09T16:42:51Z

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

sched_ext: Add cgroup support

2024-09-04T20:24:59Z

Add sched_ext_ops operations to init/exit cgroups, and track task migrations and config changes. A BPF scheduler may not implement or implement only subset of cgroup features. The implemented features can be indicated using %SCX_OPS_HAS_CGOUP_* flags. If cgroup configuration makes use of features that are not implemented, a warning is triggered. While a BPF scheduler is being enabled and disabled, relevant cgroup operations are locked out using scx_cgroup_rwsem. This avoids situations like task prep taking place while the task is being moved across cgroups, making things easier for BPF schedulers. v7: - cgroup interface file visibility toggling is dropped in favor just warning messages. Dynamically changing interface visiblity caused more confusion than helping. v6: - Updated to reflect the removal of SCX_KF_SLEEPABLE. - Updated to use CONFIG_GROUP_SCHED_WEIGHT and fixes for !CONFIG_FAIR_GROUP_SCHED && CONFIG_EXT_GROUP_SCHED. v5: - Flipped the locking order between scx_cgroup_rwsem and cpus_read_lock() to avoid locking order conflict w/ cpuset. Better documentation around locking. - sched_move_task() takes an early exit if the source and destination are identical. This triggered the warning in scx_cgroup_can_attach() as it left p->scx.cgrp_moving_from uncleared. Updated the cgroup migration path so that ops.cgroup_prep_move() is skipped for identity migrations so that its invocations always match ops.cgroup_move() one-to-one. v4: - Example schedulers moved into their own patches. - Fix build failure when !CONFIG_CGROUP_SCHED, reported by Andrea Righi. v3: - Make scx_example_pair switch all tasks by default. - Convert to BPF inline iterators. - scx_bpf_task_cgroup() is added to determine the current cgroup from CPU controller's POV. This allows BPF schedulers to accurately track CPU cgroup membership. - scx_example_flatcg added. This demonstrates flattened hierarchy implementation of CPU cgroup control and shows significant performance improvement when cgroups which are nested multiple levels are under competition. v2: - Build fixes for different CONFIG combinations. Signed-off-by: Tejun Heo Reviewed-by: David Vernet Acked-by: Josh Don Acked-by: Hao Luo Acked-by: Barret Rhoden Reported-by: kernel test robot Cc: Andrea Righi

scx/selftests: Verify we can call create_dsq from prog_run

2024-07-31T17:47:34Z

We already have some testcases verifying that we can call BPF_PROG_TYPE_SYSCALL progs and invoke scx_bpf_exit(). Let's extend that to also call scx_bpf_create_dsq() so we get coverage for that as well. Signed-off-by: David Vernet Signed-off-by: Tejun Heo