From 2378a191f440a06e4c60fb8a50f4cb708c10ba40 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Michal=20Koutn=C3=BD?= Date: Wed, 24 Sep 2025 13:38:09 +0200 Subject: [PATCH] tracing: Ensure optimized hashing works MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit If ever PID_MAX_DEFAULT changes, it must be compatible with tracing hashmaps assumptions. Cc: Masami Hiramatsu Cc: Mathieu Desnoyers Link: https://lore.kernel.org/20250924113810.2433478-1-mkoutny@suse.com Link: https://lore.kernel.org/r/20240409110126.651e94cb@gandalf.local.home/ Signed-off-by: Michal Koutný Signed-off-by: Steven Rostedt (Google) --- 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); /* -- 2.47.3