Re: [PATCH 1/2] hung_task: Show the blocker task if the task is hung on mutex

[Steven Rostedt <rostedt@xxxxxxxxxxx>]

On Thu, 20 Feb 2025 08:09:08 +0900
Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx> wrote:

> So something like this?
> 
> unsigned int	block_flags;
> union {
> 	struct mutex	*mutex;
> 	struct rwsem	+rwsem;
> 	struct rtmutex	*rtmutex;
> } blocked_on;
> 
> enum {
> 	BLOCKED_ON_MUTEX;
> 	BLOCKED_ON_RWSEM;
> 	BLOCKED_ON_RTMUTEX;
> 	BLOCKED_ON_IO;
> } block_reason;
> 
> For the safety, we may anyway lock the task anyway, but that is the
> same as stacktrace.

Why not make it into a single entity?

struct blocked_on {
	unsigned int	flags;
	union {
		struct mutex	*mutex;
		struct rwsem	*rwsem;
		struct rtmutex	*rtmutex;
	} blocked_on;
};

-- Steve