sched_ext: Documentation: clarify arena-backed doubly-linked lists in scx_qmap

Update scx_qmap description to reflect arena-backed doubly-linked
lists with per-queue bpf_res_spin_lock.

Also update scx_qmap.bpf.c to reflect switch from PIDs to TIDs.

Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Cheng-Yang Chou <yphbchou0911@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

diff --git a/Documentation/scheduler/sched-ext.rst b/Documentation/scheduler/sched-ext.rst
index fba09aa1cd4e7648d8165446e00a5bf3ac32a16a..c4f59c08d8a4f06a40dfc25240f1c5855754d241 100644 (file)
--- a/Documentation/scheduler/sched-ext.rst
+++ b/Documentation/scheduler/sched-ext.rst
@@ -508,7 +508,7 @@ Where to Look
     custom DSQ.
 
   * ``scx_qmap[.bpf].c``: A multi-level FIFO scheduler supporting five
-    levels of priority implemented with ``BPF_MAP_TYPE_QUEUE``.
+    levels of priority implemented with arena-backed doubly-linked lists.
 
   * ``scx_central[.bpf].c``: A central FIFO scheduler where all scheduling
     decisions are made on one CPU, demonstrating ``LOCAL_ON`` dispatching,

diff --git a/tools/sched_ext/README.md b/tools/sched_ext/README.md
index 6e282bce453cce501a14c73a9fe2e16c2eb5318a..0ee5a3d997e5d01b73ea93ea82786611c498be7d 100644 (file)
--- a/tools/sched_ext/README.md
+++ b/tools/sched_ext/README.md
@@ -168,9 +168,9 @@ well on single-socket systems with a unified L3 cache.
 
 Another simple, yet slightly more complex scheduler that provides an example of
 a basic weighted FIFO queuing policy. It also provides examples of some common
-useful BPF features, such as sleepable per-task storage allocation in the
-`ops.prep_enable()` callback, and using the `BPF_MAP_TYPE_QUEUE` map type to
-enqueue tasks. It also illustrates how core-sched support could be implemented.
+useful BPF features, such as arena-backed doubly-linked lists threaded through
+per-task context and `bpf_res_spin_lock` for per-queue synchronization. It also
+illustrates how core-sched support could be implemented.
 
 ## scx_central
 

diff --git a/tools/sched_ext/scx_qmap.bpf.c b/tools/sched_ext/scx_qmap.bpf.c
index 2f4c45f6544d861a5252a35c5bba1e2f8767e0d4..a73a2dcbaeb73904f28ea3e6d120eb88ee0f0486 100644 (file)
--- a/tools/sched_ext/scx_qmap.bpf.c
+++ b/tools/sched_ext/scx_qmap.bpf.c
@@ -10,7 +10,7 @@
  *
  * This scheduler demonstrates:
  *
- * - BPF-side queueing using PIDs.
+ * - BPF-side queueing using TIDs.
  * - BPF arena for scheduler state.
  * - Core-sched support.
  *