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

Pull in 57ccf5ccdc ("sched_ext: Fix enqueue_task_scx() truncation of
upper enqueue flags") which conflicts with ebf1ccff79 ("sched_ext: Fix
ops.dequeue() semantics").

Signed-off-by: Tejun Heo <tj@kernel.org>

# Conflicts:
#	kernel/sched/ext.c

Documentation/scheduler/sched-ext.rst

@@ -43,7 +43,6 @@ options should be enabled to use sched_ext:
     CONFIG_DEBUG_INFO_BTF=y
     CONFIG_BPF_JIT_ALWAYS_ON=y
     CONFIG_BPF_JIT_DEFAULT_ON=y
-    CONFIG_PAHOLE_HAS_BTF_TAG=y
 
 sched_ext is used only when the BPF scheduler is loaded and running.
 
@@ -410,6 +409,8 @@ Where to Look
   The functions prefixed with ``scx_bpf_`` can be called from the BPF
   scheduler.
 
+* ``kernel/sched/ext_idle.c`` contains the built-in idle CPU selection policy.
+
 * ``tools/sched_ext/`` hosts example BPF scheduler implementations.
 
   * ``scx_simple[.bpf].c``: Minimal global FIFO scheduler example using a
@@ -418,13 +419,35 @@ Where to Look
   * ``scx_qmap[.bpf].c``: A multi-level FIFO scheduler supporting five
     levels of priority implemented with ``BPF_MAP_TYPE_QUEUE``.
 
+  * ``scx_central[.bpf].c``: A central FIFO scheduler where all scheduling
+    decisions are made on one CPU, demonstrating ``LOCAL_ON`` dispatching,
+    tickless operation, and kthread preemption.
+
+  * ``scx_cpu0[.bpf].c``: A scheduler that queues all tasks to a shared DSQ
+    and only dispatches them on CPU0 in FIFO order. Useful for testing bypass
+    behavior.
+
+  * ``scx_flatcg[.bpf].c``: A flattened cgroup hierarchy scheduler
+    implementing hierarchical weight-based cgroup CPU control by compounding
+    each cgroup's share at every level into a single flat scheduling layer.
+
+  * ``scx_pair[.bpf].c``: A core-scheduling example that always makes
+    sibling CPU pairs execute tasks from the same CPU cgroup.
+
+  * ``scx_sdt[.bpf].c``: A variation of ``scx_simple`` demonstrating BPF
+    arena memory management for per-task data.
+
+  * ``scx_userland[.bpf].c``: A minimal scheduler demonstrating user space
+    scheduling. Tasks with CPU affinity are direct-dispatched in FIFO order;
+    all others are scheduled in user space by a simple vruntime scheduler.
+
 ABI Instability
 ===============
 
 The APIs provided by sched_ext to BPF schedulers programs have no stability
 guarantees. This includes the ops table callbacks and constants defined in
 ``include/linux/sched/ext.h``, as well as the ``scx_bpf_`` kfuncs defined in
-``kernel/sched/ext.c``.
+``kernel/sched/ext.c`` and ``kernel/sched/ext_idle.c``.
 
 While we will attempt to provide a relatively stable API surface when
 possible, they are subject to change without warning between kernel

kernel/sched/ext.c

@@ -1728,16 +1728,15 @@ static void clr_task_runnable(struct task_struct *p, bool reset_runnable_at)
 		p->scx.flags |= SCX_TASK_RESET_RUNNABLE_AT;
 }
 
-static void enqueue_task_scx(struct rq *rq, struct task_struct *p, int enq_flags)
+static void enqueue_task_scx(struct rq *rq, struct task_struct *p, int core_enq_flags)
 {
 	struct scx_sched *sch = scx_task_sched(p);
 	int sticky_cpu = p->scx.sticky_cpu;
+	u64 enq_flags = core_enq_flags | rq->scx.extra_enq_flags;
 
 	if (enq_flags & ENQUEUE_WAKEUP)
 		rq->scx.flags |= SCX_RQ_IN_WAKEUP;
 
-	enq_flags |= rq->scx.extra_enq_flags;
-
 	/*
 	 * Restoring a running task will be immediately followed by
 	 * set_next_task_scx() which expects the task to not be on the BPF