kernel/git/next/linux-next.git/tools/sched_ext/include, branch master

sched_ext: Make scx_bpf_kick_cid() return void

2026-07-09T22:06:11+00:00

scx_bpf_kick_cid() returned an error code, but the value conveys nothing actionable and no caller consumes it. The kick is asynchronous, so a successful return only means it was queued. An invalid @cid is already reported through scx_error() by scx_cid_to_cpu(), and a missing scheduler leaves nothing to kick. Make scx_bpf_kick_cid() return void to match scx_bpf_kick_cpu(). The cid-form kfuncs are not in practical use yet, so the ABI change is safe. Signed-off-by: Tejun Heo Reviewed-by: Andrea Righi

Merge branch 'for-7.2-fixes' into for-7.3

2026-07-09T21:41:10+00:00

Pull to receive: db4e9defd2e8 ("sched_ext: Record an error on errno-only sub-enable failure") 49b3378a750c ("sched_ext: Fix premature ops->priv publication in scx_alloc_and_add_sched()") e6979d05c6a6 ("tools/sched_ext: scx - Fix cmask_subset(), cmask_equal() and cmask_weight()") for further sub-sched changes and to resolve the conflicts with the sub-sched updates on for-7.3. db4e9defd2e8 adds scx_error() to the sub-enable err_disable sink which for-7.3 moved from ext.c into sub.c. Resolved by applying the fix to scx_sub_enable_workfn() in sub.c. 49b3378a750c drops RCU_INIT_POINTER() from an scx_alloc_and_add_sched() unwind label whose body changed with for-7.3's stall_cpus addition. Resolved by dropping the line from the updated unwind. Signed-off-by: Tejun Heo

tools/sched_ext: scx - Fix cmask_subset(), cmask_equal() and cmask_weight()

2026-07-09T21:08:41+00:00

cmask_equal(), cmask_weight() and cmask_subset() bounded their word walks with CMASK_NR_WORDS(nr_cids), which pads by one word and can't tell the last word in use without @base. The walks could thus cover a slack word past the active range, which cmask_reframe() leaves non-zero: a stale bit there gave cmask_equal() a spurious mismatch, cmask_weight() an inflated count, and cmask_subset() a spurious violation. cmask_subset() could also read @b->bits[] one word past its allocation (within the arena's fault-recovered range, so harmless), and deviated from the kernel scx_cmask_subset() by failing any @a range that doesn't nest inside @b's even when the overhanging bits are all clear. Bound the cmask_equal() and cmask_weight() walks by the words the range actually spans, with early returns for empty ranges. Rewrite cmask_subset() to match the kernel semantics: scan @a's overhangs for set bits with cmask_next_set() and walk the words of the range intersection. cmask_subset() moves below cmask_next_set(), which it now uses. Padding bits don't need masking as every cmask helper keeps them clear. Fixes: a58e6b79b432 ("sched_ext: Add cmask, a base-windowed bitmap over cid space") Signed-off-by: Tejun Heo Reviewed-by: Andrea Righi

tools/sched_ext: use btf_vlen() helper in compat.h

2026-06-30T14:09:33+00:00

__COMPAT_read_enum() and __COMPAT_struct_has_field() open-code the vlen lookup via the raw BTF_INFO_VLEN(t->info) UAPI macro. libbpf exposes btf_vlen() for exactly this purpose; use it in the three call sites, matching the pattern in kernel/bpf/inode.c and tools/bpf/bpftool. btf_vlen() returns __u32 (since commit cacd6729c0923, "libbpf: Adjust btf_vlen() to return a __u32", which expanded the BTF vlen field from 16 to 24 bits). Declare the loop counters as __u32 to match the return type, keeping the comparison as a plain '__u32 < __u32' and silencing the -Wsign-compare warnings. No functional change. Suggested-by: Andrea Righi Signed-off-by: Liang Luo Reviewed-by: Andrea Righi Signed-off-by: Tejun Heo

sched_ext: Remove deprecated scx_bpf_cpu_rq()

2026-06-24T22:48:32+00:00

scx_bpf_cpu_rq() exposes rq pointers without requiring the rq lock and has emitted a deprecation warning since commit 5c48d88fe004 ("sched_ext: deprecation warn for scx_bpf_cpu_rq()"). The supported replacements cover the intended uses: scx_bpf_locked_rq() for locked rq access and scx_bpf_cpu_curr() for remote curr lookup. Remove the kfunc, its BTF registrations, the deprecation warning state, and the BPF-side prototype and compat fallback. Signed-off-by: Christian Loehle Reviewed-by: Andrea Righi Reviewed-by: Hongyan Xia Signed-off-by: Tejun Heo

sched_ext: Move sources under kernel/sched/ext/

2026-06-22T15:32:56+00:00

The sched_ext sources had grown to ten ext* files directly under kernel/sched/. Move them into a new kernel/sched/ext/ subdirectory and drop the now-redundant ext_ prefix. ext.c/h keep their names. kernel/sched/ext.{c,h} -> kernel/sched/ext/ext.{c,h} kernel/sched/ext_internal.h -> kernel/sched/ext/internal.h kernel/sched/ext_types.h -> kernel/sched/ext/types.h kernel/sched/ext_idle.{c,h} -> kernel/sched/ext/idle.{c,h} kernel/sched/ext_cid.{c,h} -> kernel/sched/ext/cid.{c,h} kernel/sched/ext_arena.{c,h} -> kernel/sched/ext/arena.{c,h} The include paths in build_policy.c and sched.h, the MAINTAINERS glob, and a few documentation and comment references are updated to match. No code or symbol changes. Suggested-by: Linus Torvalds Reviewed-by: Andrea Righi Signed-off-by: Tejun Heo

sched_ext: Make scx_bpf_kick_cid() return s32

2026-06-04T01:46:56+00:00

Switch scx_bpf_kick_cid() from void to s32 so future cap enforcement can surface failures. cid interface is introduced in this cycle and has no external users, so the ABI change is safe. Subsequent patches will add -EPERM returns when the calling sub-sched lacks the required cap on the target cid. v2: Return scx_cid_to_cpu()'s errno instead of -EINVAL. (Andrea) Signed-off-by: Tejun Heo Reviewed-by: Andrea Righi

tools/sched_ext: Order single-cid cmask helpers as (cid, mask)

2026-06-04T01:46:56+00:00

The BPF arena single-cid cmask helpers take the cmask first and the cid second. Reorder them to (cid, mask) to match the kernel-side helpers and the test_bit(nr, addr), cpumask_test_cpu(cpu, mask) convention. Range and iteration helpers keep (mask, start). Signed-off-by: Tejun Heo Reviewed-by: Andrea Righi

sched_ext: Convert ops.set_cmask() to arena-resident cmask

2026-05-25T19:44:07+00:00

ops_cid.set_cmask() expects a cmask. The kernel couldn't write into the arena, so it translated cpumask -> cmask in kernel memory and passed the result as a trusted pointer. The BPF cmask helpers all operate on arena cmasks though, so the BPF side had to word-by-word probe-read the kernel cmask into an arena cmask via cmask_copy_from_kernel() before any helper could touch it. It works, but is clumsy. With direct kernel-side arena access now in place, build the cmask in the arena. The kernel writes to it through the kern_va side of the dual mapping. BPF directly dereferences it via an __arena pointer like any other arena struct. Signed-off-by: Tejun Heo Reviewed-by: Emil Tsalapatis

sched_ext: Track bits[] storage size in struct scx_cmask

2026-05-21T07:14:39+00:00

scx_cmask carries @base and @nr_cids but not the bits[] allocation size, so helpers reshaping the active range have no way to check it fits and later kfuncs taking caller-provided storage can't validate it. Add @alloc_words (u64 word count) annotated with __counted_by, and split the bit-range API into three helpers: - SCX_CMASK_DEFINE() / __SCX_CMASK_DEFINE() define an on-stack cmask, the latter taking an explicit capacity for oversized storage. SCX_CMASK_DEFINE_SHARD() is a thin wrapper that always reserves SCX_CID_SHARD_MAX_CPUS bits of storage. - scx_cmask_init() / __scx_cmask_init() initialize a cmask, with the same tight-vs-explicit split. - scx_cmask_reframe() reshapes the active range without resizing storage. The BPF mirror (cmask_init / __cmask_init / cmask_reframe) gets the same shape. Add scx_cmask_clear() and scx_cmask_fill() to zero and set the active-range bits respectively. scx_cpumask_to_cmask() uses scx_cmask_clear(); scx_cmask_init() would otherwise re-write @alloc_words on every call. A later patch uses @alloc_words in scx_cmask_ref_shard() to refuse output storage that can't hold the requested shard. v2: Init per-CPU scx_set_cmask_scratch (was zero-init, emitted empty cmasks). Add nr_cids/alloc_cids check in BPF __cmask_init(). (sashiko AI) Widen SCX_CMASK_NR_WORDS()/CMASK_NR_WORDS() to compute in u64 so that @nr_cids near U32_MAX no longer wraps to a small value and bypasses the bounds check in cmask_reframe(). (Andrea) Signed-off-by: Tejun Heo Reviewed-by: Andrea Righi