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Date:   Mon, 6 Nov 2023 19:45:00 -0500
From:   Steven Rostedt <rostedt@goodmis.org>
To:     =?UTF-8?B?xYF1a2Fzeg==?= Bartosik <lb@semihalf.com>
Cc:     Jason Baron <jbaron@akamai.com>, Jim Cromie <jim.cromie@gmail.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Kees Cook <keescook@chromium.org>,
        Douglas Anderson <dianders@chromium.org>,
        Guenter Roeck <groeck@google.com>,
        Yaniv Tzoreff <yanivt@google.com>,
        Benson Leung <bleung@google.com>,
        Vincent Whitchurch <vincent.whitchurch@axis.com>,
        Pekka Paalanen <ppaalanen@gmail.com>,
        Sean Paul <seanpaul@chromium.org>,
        Daniel Vetter <daniel@ffwll.ch>, linux-kernel@vger.kernel.org,
        upstream@semihalf.com
Subject: Re: [PATCH v1 06/12] trace: use TP_printk_no_nl in
 dyndbg:prdbg,devdbg
Message-ID: <20231106194500.123a517e@gandalf.local.home>
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        <20231103131011.1316396-7-lb@semihalf.com>
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On Fri,  3 Nov 2023 14:10:05 +0100
Łukasz Bartosik <lb@semihalf.com> wrote:

> index ccc5bcb070f9..91dcdbe059c0 100644
> --- a/include/trace/events/dyndbg.h
> +++ b/include/trace/events/dyndbg.h
> @@ -20,20 +20,10 @@ TRACE_EVENT(prdbg,
>  
>  	    TP_fast_assign(
>  			__entry->desc = desc;
> -			/*
> -			 * Each trace entry is printed in a new line.
> -			 * If the msg finishes with '\n', cut it off
> -			 * to avoid blank lines in the trace.
> -			 */
> -			if (len > 0 && (text[len - 1] == '\n'))
> -				len -= 1;
> -
>  			memcpy(__get_str(msg), text, len);
> -			__get_str(msg)[len] = 0;
>  		    ),
>  
> -	    TP_printk("%s.%s %s", __entry->desc->modname,
> -		      __entry->desc->function, __get_str(msg))
> +	    TP_printk_no_nl("%s", __get_str(msg))
>  );
>  

Instead of adding the TP_printk_no_nl() (Which I still do not like), we
could add a:

	__get_str_strip_nl(msg)

That will do the above loop. Which will move the processing to read side
(slow path).

And then we could update libtraceevent to handle that too.

-- Steve