linux-kernel - Re: [PATCH v2 2/9] perf evsel: Avoid close(-1)

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Date:   Tue, 22 Oct 2019 10:01:15 +0200
From:   Jiri Olsa <jolsa@...hat.com>
To:     Andi Kleen <andi@...stfloor.org>
Cc:     acme@...nel.org, linux-kernel@...r.kernel.org, jolsa@...nel.org,
        eranian@...gle.com, kan.liang@...ux.intel.com,
        peterz@...radead.org, Andi Kleen <ak@...ux.intel.com>
Subject: Re: [PATCH v2 2/9] perf evsel: Avoid close(-1)

On Sun, Oct 20, 2019 at 10:51:55AM -0700, Andi Kleen wrote:
> From: Andi Kleen <ak@...ux.intel.com>
> 
> In some weak fallback cases close can be called a lot with -1. Check
> for this case and avoid calling close then.
> 
> This is mainly to shut up valgrind which complains about this case.
> 
> Signed-off-by: Andi Kleen <ak@...ux.intel.com>

Acked-by: Jiri Olsa <jolsa@...nel.org>

thanks,
jirka

> ---
>  tools/perf/lib/evsel.c  | 3 ++-
>  tools/perf/util/evsel.c | 3 ++-
>  2 files changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/perf/lib/evsel.c b/tools/perf/lib/evsel.c
> index a8cb582e2721..5a89857b0381 100644
> --- a/tools/perf/lib/evsel.c
> +++ b/tools/perf/lib/evsel.c
> @@ -120,7 +120,8 @@ void perf_evsel__close_fd(struct perf_evsel *evsel)
>  
>  	for (cpu = 0; cpu < xyarray__max_x(evsel->fd); cpu++)
>  		for (thread = 0; thread < xyarray__max_y(evsel->fd); ++thread) {
> -			close(FD(evsel, cpu, thread));
> +			if (FD(evsel, cpu, thread) >= 0)
> +				close(FD(evsel, cpu, thread));
>  			FD(evsel, cpu, thread) = -1;
>  		}
>  }
> diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
> index d831038b55f2..d4451846af93 100644
> --- a/tools/perf/util/evsel.c
> +++ b/tools/perf/util/evsel.c
> @@ -1815,7 +1815,8 @@ int evsel__open(struct evsel *evsel, struct perf_cpu_map *cpus,
>  	old_errno = errno;
>  	do {
>  		while (--thread >= 0) {
> -			close(FD(evsel, cpu, thread));
> +			if (FD(evsel, cpu, thread) >= 0)
> +				close(FD(evsel, cpu, thread));
>  			FD(evsel, cpu, thread) = -1;
>  		}
>  		thread = nthreads;
> -- 
> 2.21.0
>