[for-next][PATCH 10/11] tracing: Ensure optimized hashing works

[Steven Rostedt]

From: =?UTF-8?q?Michal=20Koutn=C3=BD?= <mkoutny@xxxxxxxx>

If ever PID_MAX_DEFAULT changes, it must be compatible with tracing
hashmaps assumptions.

Cc: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Cc: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
Link: https://lore.kernel.org/20250924113810.2433478-1-mkoutny@xxxxxxxx
Link: https://lore.kernel.org/r/20240409110126.651e94cb@xxxxxxxxxxxxxxxxxx/
Signed-off-by: Michal Koutný <mkoutny@xxxxxxxx>
Signed-off-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx>
---
 kernel/trace/trace_sched_switch.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c
index 518dfc74347a..c46d584ded3b 100644
--- a/kernel/trace/trace_sched_switch.c
+++ b/kernel/trace/trace_sched_switch.c
@@ -247,6 +247,8 @@ int trace_save_cmdline(struct task_struct *tsk)
 	if (!tsk->pid)
 		return 1;
 
+	BUILD_BUG_ON(!is_power_of_2(PID_MAX_DEFAULT));
+
 	tpid = tsk->pid & (PID_MAX_DEFAULT - 1);
 
 	/*
-- 
2.50.1