linux-kernel - Re: [PATCH 1/3] perf lock contention: Handle error in a single place

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Message-ID: <ZtHGbFyJYLzzVRou@x1>
Date: Fri, 30 Aug 2024 10:17:32 -0300
From: Arnaldo Carvalho de Melo <acme@...nel.org>
To: Namhyung Kim <namhyung@...nel.org>
Cc: Ian Rogers <irogers@...gle.com>, Kan Liang <kan.liang@...ux.intel.com>,
	Jiri Olsa <jolsa@...nel.org>,
	Adrian Hunter <adrian.hunter@...el.com>,
	Peter Zijlstra <peterz@...radead.org>,
	Ingo Molnar <mingo@...nel.org>, LKML <linux-kernel@...r.kernel.org>,
	linux-perf-users@...r.kernel.org, Song Liu <song@...nel.org>,
	bpf@...r.kernel.org
Subject: Re: [PATCH 1/3] perf lock contention: Handle error in a single place

On Thu, Aug 29, 2024 at 11:51:48PM -0700, Namhyung Kim wrote:
> It has some duplicate codes to do the same job.  Let's add a label and
> goto there to handle errors in a single place.

Thanks, applied to perf-tools-next,

- Arnaldo
 
> Signed-off-by: Namhyung Kim <namhyung@...nel.org>
> ---
>  tools/perf/util/bpf_skel/lock_contention.bpf.c | 16 ++++------------
>  1 file changed, 4 insertions(+), 12 deletions(-)
> 
> diff --git a/tools/perf/util/bpf_skel/lock_contention.bpf.c b/tools/perf/util/bpf_skel/lock_contention.bpf.c
> index d931a898c434..e8a6f6463019 100644
> --- a/tools/perf/util/bpf_skel/lock_contention.bpf.c
> +++ b/tools/perf/util/bpf_skel/lock_contention.bpf.c
> @@ -439,11 +439,8 @@ int contention_end(u64 *ctx)
>  
>  	duration = bpf_ktime_get_ns() - pelem->timestamp;
>  	if ((__s64)duration < 0) {
> -		pelem->lock = 0;
> -		if (need_delete)
> -			bpf_map_delete_elem(&tstamp, &pid);
>  		__sync_fetch_and_add(&time_fail, 1);
> -		return 0;
> +		goto out;
>  	}
>  
>  	switch (aggr_mode) {
> @@ -477,11 +474,8 @@ int contention_end(u64 *ctx)
>  	data = bpf_map_lookup_elem(&lock_stat, &key);
>  	if (!data) {
>  		if (data_map_full) {
> -			pelem->lock = 0;
> -			if (need_delete)
> -				bpf_map_delete_elem(&tstamp, &pid);
>  			__sync_fetch_and_add(&data_fail, 1);
> -			return 0;
> +			goto out;
>  		}
>  
>  		struct contention_data first = {
> @@ -502,10 +496,7 @@ int contention_end(u64 *ctx)
>  				data_map_full = 1;
>  			__sync_fetch_and_add(&data_fail, 1);
>  		}
> -		pelem->lock = 0;
> -		if (need_delete)
> -			bpf_map_delete_elem(&tstamp, &pid);
> -		return 0;
> +		goto out;
>  	}
>  
>  	__sync_fetch_and_add(&data->total_time, duration);
> @@ -517,6 +508,7 @@ int contention_end(u64 *ctx)
>  	if (data->min_time > duration)
>  		data->min_time = duration;
>  
> +out:
>  	pelem->lock = 0;
>  	if (need_delete)
>  		bpf_map_delete_elem(&tstamp, &pid);
> -- 
> 2.46.0.469.g59c65b2a67-goog