kernel/tools/testing/selftests/sched_ext/maximal.bpf.c, branch linux-rolling-stable

sched_ext: Add support for cgroup bandwidth control interface

2025-06-21T03:03:51Z

From 077814f57f8acce13f91dc34bbd2b7e4911fbf25 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Fri, 13 Jun 2025 15:06:47 -1000 - Add CONFIG_GROUP_SCHED_BANDWIDTH which is selected by both CONFIG_CFS_BANDWIDTH and EXT_GROUP_SCHED. - Put bandwidth control interface files for both cgroup v1 and v2 under CONFIG_GROUP_SCHED_BANDWIDTH. - Update tg_bandwidth() to fetch configuration parameters from fair if CONFIG_CFS_BANDWIDTH, SCX otherwise. - Update tg_set_bandwidth() to update the parameters for both fair and SCX. - Add bandwidth control parameters to struct scx_cgroup_init_args. - Add sched_ext_ops.cgroup_set_bandwidth() which is invoked on bandwidth control parameter updates. - Update scx_qmap and maximal selftest to test the new feature. 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 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

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

sched_ext: Add selftests

2024-06-18T20:09:21Z

Add basic selftests. Signed-off-by: David Vernet Acked-by: Tejun Heo