perf: Minor fixes and cleanup

[PATCH -next 3/5] perf: Remove duplicate errbuf

Posted by Chen Zhongjin 3 years, 6 months ago

char errbuf[BUFSIZ] is defined twice in trace__run.

However out_error_open is not cross to other out_error path, they can
share one errbuf together.

Define the errbuf[BUFSIZ] at the beginning of function, and remove the
redefinations of them for code cleaning.

Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com>
---
 tools/perf/builtin-trace.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index 7ecd76428440..5660c0ee3507 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -3937,6 +3937,7 @@ static int trace__run(struct trace *trace, int argc, const char **argv)
 	unsigned long before;
 	const bool forks = argc > 0;
 	bool draining = false;
+	char errbuf[BUFSIZ];
 
 	trace->live = true;
 
@@ -4027,8 +4028,6 @@ static int trace__run(struct trace *trace, int argc, const char **argv)
 
 	err = bpf__apply_obj_config();
 	if (err) {
-		char errbuf[BUFSIZ];
-
 		bpf__strerror_apply_obj_config(err, errbuf, sizeof(errbuf));
 		pr_err("ERROR: Apply config to BPF failed: %s\n",
 			 errbuf);
@@ -4185,8 +4184,6 @@ static int trace__run(struct trace *trace, int argc, const char **argv)
 	trace->evlist = NULL;
 	trace->live = false;
 	return err;
-{
-	char errbuf[BUFSIZ];
 
 out_error_sched_stat_runtime:
 	tracing_path__strerror_open_tp(errno, errbuf, sizeof(errbuf), "sched", "sched_stat_runtime");
@@ -4213,7 +4210,7 @@ static int trace__run(struct trace *trace, int argc, const char **argv)
 		evsel->filter, evsel__name(evsel), errno,
 		str_error_r(errno, errbuf, sizeof(errbuf)));
 	goto out_delete_evlist;
-}
+
 out_error_mem:
 	fprintf(trace->output, "Not enough memory to run!\n");
 	goto out_delete_evlist;
-- 
2.17.1

Re: [PATCH -next 3/5] perf: Remove duplicate errbuf

Posted by Arnaldo Carvalho de Melo 3 years, 6 months ago

Em Mon, Sep 26, 2022 at 11:14:38AM +0800, Chen Zhongjin escreveu:
> char errbuf[BUFSIZ] is defined twice in trace__run.
> 
> However out_error_open is not cross to other out_error path, they can
> share one errbuf together.
> 
> Define the errbuf[BUFSIZ] at the beginning of function, and remove the
> redefinations of them for code cleaning.

Have you looked at the end result in the generated code? Just out of
curiosity.

- Arnaldo
 
> Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com>
> ---
>  tools/perf/builtin-trace.c | 7 ++-----
>  1 file changed, 2 insertions(+), 5 deletions(-)
> 
> diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
> index 7ecd76428440..5660c0ee3507 100644
> --- a/tools/perf/builtin-trace.c
> +++ b/tools/perf/builtin-trace.c
> @@ -3937,6 +3937,7 @@ static int trace__run(struct trace *trace, int argc, const char **argv)
>  	unsigned long before;
>  	const bool forks = argc > 0;
>  	bool draining = false;
> +	char errbuf[BUFSIZ];
>  
>  	trace->live = true;
>  
> @@ -4027,8 +4028,6 @@ static int trace__run(struct trace *trace, int argc, const char **argv)
>  
>  	err = bpf__apply_obj_config();
>  	if (err) {
> -		char errbuf[BUFSIZ];
> -
>  		bpf__strerror_apply_obj_config(err, errbuf, sizeof(errbuf));
>  		pr_err("ERROR: Apply config to BPF failed: %s\n",
>  			 errbuf);
> @@ -4185,8 +4184,6 @@ static int trace__run(struct trace *trace, int argc, const char **argv)
>  	trace->evlist = NULL;
>  	trace->live = false;
>  	return err;
> -{
> -	char errbuf[BUFSIZ];
>  
>  out_error_sched_stat_runtime:
>  	tracing_path__strerror_open_tp(errno, errbuf, sizeof(errbuf), "sched", "sched_stat_runtime");
> @@ -4213,7 +4210,7 @@ static int trace__run(struct trace *trace, int argc, const char **argv)
>  		evsel->filter, evsel__name(evsel), errno,
>  		str_error_r(errno, errbuf, sizeof(errbuf)));
>  	goto out_delete_evlist;
> -}
> +
>  out_error_mem:
>  	fprintf(trace->output, "Not enough memory to run!\n");
>  	goto out_delete_evlist;
> -- 
> 2.17.1

-- 

- Arnaldo

Re: [PATCH -next 3/5] perf: Remove duplicate errbuf

Posted by Chen Zhongjin 3 years, 6 months ago

Hi,

On 2022/9/27 3:54, Arnaldo Carvalho de Melo wrote:
> Em Mon, Sep 26, 2022 at 11:14:38AM +0800, Chen Zhongjin escreveu:
>> char errbuf[BUFSIZ] is defined twice in trace__run.
>>
>> However out_error_open is not cross to other out_error path, they can
>> share one errbuf together.
>>
>> Define the errbuf[BUFSIZ] at the beginning of function, and remove the
>> redefinations of them for code cleaning.
> Have you looked at the end result in the generated code? Just out of
> curiosity.

Good question. Because it is an auto reported warning of clang I didn't 
try it.

Just tried and found no different for 'objdump -d perf' on two version.


Best,

Chen

>
> - Arnaldo
>   
>> Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com>
>> ---
>>   tools/perf/builtin-trace.c | 7 ++-----
>>   1 file changed, 2 insertions(+), 5 deletions(-)
>>
>> diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
>> index 7ecd76428440..5660c0ee3507 100644
>> --- a/tools/perf/builtin-trace.c
>> +++ b/tools/perf/builtin-trace.c
>> @@ -3937,6 +3937,7 @@ static int trace__run(struct trace *trace, int argc, const char **argv)
>>   	unsigned long before;
>>   	const bool forks = argc > 0;
>>   	bool draining = false;
>> +	char errbuf[BUFSIZ];
>>   
>>   	trace->live = true;
>>   
>> @@ -4027,8 +4028,6 @@ static int trace__run(struct trace *trace, int argc, const char **argv)
>>   
>>   	err = bpf__apply_obj_config();
>>   	if (err) {
>> -		char errbuf[BUFSIZ];
>> -
>>   		bpf__strerror_apply_obj_config(err, errbuf, sizeof(errbuf));
>>   		pr_err("ERROR: Apply config to BPF failed: %s\n",
>>   			 errbuf);
>> @@ -4185,8 +4184,6 @@ static int trace__run(struct trace *trace, int argc, const char **argv)
>>   	trace->evlist = NULL;
>>   	trace->live = false;
>>   	return err;
>> -{
>> -	char errbuf[BUFSIZ];
>>   
>>   out_error_sched_stat_runtime:
>>   	tracing_path__strerror_open_tp(errno, errbuf, sizeof(errbuf), "sched", "sched_stat_runtime");
>> @@ -4213,7 +4210,7 @@ static int trace__run(struct trace *trace, int argc, const char **argv)
>>   		evsel->filter, evsel__name(evsel), errno,
>>   		str_error_r(errno, errbuf, sizeof(errbuf)));
>>   	goto out_delete_evlist;
>> -}
>> +
>>   out_error_mem:
>>   	fprintf(trace->output, "Not enough memory to run!\n");
>>   	goto out_delete_evlist;
>> -- 
>> 2.17.1