[PATCH v3 1/2] tools/sched_ext: Add missing -c option in scx_qmap help

From: Zhao Mengmeng

Date: Fri Apr 17 2026 - 05:23:02 EST


From: Zhao Mengmeng <zhaomengmeng@xxxxxxxxxx>

The sub-scheduler api has been added to scx_qmap, but the new -c option is
missing in help, which is hard to understand and use. Add it in help.

V2: add [-c CG_PATH] to the usage synopsis.

Signed-off-by: Zhao Mengmeng <zhaomengmeng@xxxxxxxxxx>
Reviewed-by: Cheng-Yang Chou <yphbchou0911@xxxxxxxxx>
---
tools/sched_ext/scx_qmap.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/tools/sched_ext/scx_qmap.c b/tools/sched_ext/scx_qmap.c
index 4bdcc4bc5fbd..725c4880058d 100644
--- a/tools/sched_ext/scx_qmap.c
+++ b/tools/sched_ext/scx_qmap.c
@@ -23,7 +23,8 @@ const char help_fmt[] =
"See the top-level comment in .bpf.c for more details.\n"
"\n"
"Usage: %s [-s SLICE_US] [-e COUNT] [-t COUNT] [-T COUNT] [-l COUNT] [-b COUNT]\n"
-" [-N COUNT] [-P] [-M] [-H] [-d PID] [-D LEN] [-S] [-p] [-I] [-F COUNT] [-v]\n"
+" [-N COUNT] [-P] [-M] [-H] [-c CG_PATH] [-d PID] [-D LEN] [-S] [-p] [-I]\n"
+" [-F COUNT] [-v]\n"
"\n"
" -s SLICE_US Override slice duration\n"
" -e COUNT Trigger scx_bpf_error() after COUNT enqueues\n"
@@ -35,6 +36,7 @@ const char help_fmt[] =
" -P Print out DSQ content and event counters to trace_pipe every second\n"
" -M Print out debug messages to trace_pipe\n"
" -H Boost nice -20 tasks in SHARED_DSQ, use with -b\n"
+" -c CG_PATH Cgroup path to attach as sub-scheduler, must run parent scheduler first\n"
" -d PID Disallow a process from switching into SCHED_EXT (-1 for self)\n"
" -D LEN Set scx_exit_info.dump buffer length\n"
" -S Suppress qmap-specific debug dump\n"

--
2.43.0