linux-kernel - [PATCH] sched_ext: update scx_bpf_dsq_insert() doc for SCX_DSQ_LOCAL

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Message-ID: <20250106170309.205385-1-arighi@nvidia.com>
Date: Mon,  6 Jan 2025 18:03:09 +0100
From: Andrea Righi <arighi@...dia.com>
To: Tejun Heo <tj@...nel.org>,
	David Vernet <void@...ifault.com>,
	Changwoo Min <changwoo@...lia.com>
Cc: Jonathan Corbet <corbet@....net>,
	linux-doc@...r.kernel.or,
	linux-kernel@...r.kernel.org
Subject: [PATCH] sched_ext: update scx_bpf_dsq_insert() doc for SCX_DSQ_LOCAL_ON

With commit 5b26f7b920f7 ("sched_ext: Allow SCX_DSQ_LOCAL_ON for direct
dispatches"), scx_bpf_dsq_insert() can use SCX_DSQ_LOCAL_ON for direct
dispatch from ops.enqueue() to target the local DSQ of any CPU.

Update the documentation accordingly.

Fixes: 5b26f7b920f7 ("sched_ext: Allow SCX_DSQ_LOCAL_ON for direct dispatches")
Signed-off-by: Andrea Righi <arighi@...dia.com>
---
 Documentation/scheduler/sched-ext.rst | 6 +++---
 kernel/sched/ext.c                    | 4 +---
 2 files changed, 4 insertions(+), 6 deletions(-)

diff --git a/Documentation/scheduler/sched-ext.rst b/Documentation/scheduler/sched-ext.rst
index 6cb8b676ce03..a8ceaad63b6a 100644
--- a/Documentation/scheduler/sched-ext.rst
+++ b/Documentation/scheduler/sched-ext.rst
@@ -242,9 +242,9 @@ The following briefly shows how a waking task is scheduled and executed.
    task was inserted directly from ``ops.select_cpu()``). ``ops.enqueue()``
    can make one of the following decisions:
 
-   * Immediately insert the task into either the global or local DSQ by
-     calling ``scx_bpf_dsq_insert()`` with ``SCX_DSQ_GLOBAL`` or
-     ``SCX_DSQ_LOCAL``, respectively.
+   * Immediately insert the task into either the global or a local DSQ by
+     calling ``scx_bpf_dsq_insert()`` with one of the following options:
+     ``SCX_DSQ_GLOBAL``, ``SCX_DSQ_LOCAL``, or ``SCX_DSQ_LOCAL_ON | cpu``.
 
    * Immediately insert the task into a custom DSQ by calling
      ``scx_bpf_dsq_insert()`` with a DSQ ID which is smaller than 2^63.
diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c
index 010ce7680bbc..c9f2fbb477ed 100644
--- a/kernel/sched/ext.c
+++ b/kernel/sched/ext.c
@@ -6406,9 +6406,7 @@ __bpf_kfunc_start_defs();
  * ops.select_cpu(), and ops.dispatch().
  *
  * When called from ops.select_cpu() or ops.enqueue(), it's for direct dispatch
- * and @p must match the task being enqueued. Also, %SCX_DSQ_LOCAL_ON can't be
- * used to target the local DSQ of a CPU other than the enqueueing one. Use
- * ops.select_cpu() to be on the target CPU in the first place.
+ * and @p must match the task being enqueued.
  *
  * When called from ops.select_cpu(), @enq_flags and @dsp_id are stored, and @p
  * will be directly inserted into the corresponding dispatch queue after
-- 
2.47.1