linux-kernel - Re: [PATCH] perf trace: Avoid duplicate code in fprintf

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <b3943cc3-234f-4789-a894-314a3890ac8e@web.de>
Date: Fri, 19 Jul 2024 18:32:24 +0200
From: Markus Elfring <Markus.Elfring@....de>
To: Christian Heusel <christian@...sel.eu>, linux-perf-users@...r.kernel.org,
 kernel-janitors@...r.kernel.org
Cc: Adrian Hunter <adrian.hunter@...el.com>,
 Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
 Arnaldo Carvalho de Melo <acme@...nel.org>, Ian Rogers <irogers@...gle.com>,
 Ingo Molnar <mingo@...hat.com>, Jiri Olsa <jolsa@...nel.org>,
 Kan Liang <kan.liang@...ux.intel.com>, Mark Rutland <mark.rutland@....com>,
 Namhyung Kim <namhyung@...nel.org>, Peter Zijlstra <peterz@...radead.org>,
 LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] perf trace: Avoid duplicate code in fprintf_duration()

…
>> +++ b/tools/perf/builtin-trace.c
>> @@ -1258,12 +1258,16 @@ static size_t fprintf_duration(unsigned long t, bool calculated, FILE *fp)
>>
>>  	if (!calculated)
>>  		printed += fprintf(fp, "         ");
>> -	else if (duration >= 1.0)
>> -		printed += color_fprintf(fp, PERF_COLOR_RED, "%6.3f ms", duration);
>> -	else if (duration >= 0.01)
>> -		printed += color_fprintf(fp, PERF_COLOR_YELLOW, "%6.3f ms", duration);
>>  	else
>> -		printed += color_fprintf(fp, PERF_COLOR_NORMAL, "%6.3f ms", duration);
>> +		printed += color_fprintf(fp,
>> +					 (duration >= 1.0
>> +					 ? PERF_COLOR_RED
>> +					 : (duration >= 0.01
>> +					   ? PERF_COLOR_YELLOW
>> +					   : PERF_COLOR_NORMAL)),
>> +					 "%6.3f ms",
>> +					 duration);
>
> Why is this a desirable change?

I find it helpful to specify the affected function call only once
in such an if branch.


>                                 Folding the if-statements into the
> ternary operator makes the code quite unreadable compared to what it was
> like before and doesn't give any obvious improvement.

Do you prefer to store the result of the colour determination into another
local variable so that it can be passed as a separate parameter?

Regards,
Markus