Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Wed, 9 Aug 2023 08:54:49 -0400
From:   Steven Rostedt <rostedt@goodmis.org>
To:     Sven Schnelle <svens@linux.ibm.com>
Cc:     linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] tracing/synthetic: use union instead of casts
Message-ID: <20230809085449.453b632a@gandalf.local.home>
In-Reply-To: <20230809071459.2004931-1-svens@linux.ibm.com>
References: <20230809071459.2004931-1-svens@linux.ibm.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Precedence: bulk

On Wed,  9 Aug 2023 09:14:59 +0200
Sven Schnelle <svens@linux.ibm.com> wrote:

> --- a/kernel/trace/trace.h
> +++ b/kernel/trace/trace.h
> @@ -1295,6 +1295,16 @@ static inline void trace_branch_disable(void)
>  /* set ring buffers to default size if not already done so */
>  int tracing_update_buffers(void);
>  
> +struct trace_dynamic {
> +	union {
> +		u8				as_u8;
> +		u16				as_u16;
> +		u32				as_u32;
> +		u64				as_u64;
> +		struct trace_dynamic_info	as_dynamic;
> +	};
> +};
> +

No need to create a structure around a single element union. Also, I would
like to name it for what it is for.

union trace_synth_field {
	u8				as_u8;
	u16				as_u16;
	u32				as_u32;
	u64				as_u64;
	struct trace_dynamic_info	as_dynamic;
};

Other than that, the patch looks good. Although I still need to test it.

-- Steve