Re: [PATCH v2 03/13] perf hist: Add missing puts to hist__account_cycles

From: Namhyung Kim <namhyung@kernel.org>
To: Ian Rogers <irogers@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>,
	Ingo Molnar <mingo@redhat.com>,
	 Arnaldo Carvalho de Melo <acme@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	 Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	Jiri Olsa <jolsa@kernel.org>,
	 Adrian Hunter <adrian.hunter@intel.com>,
	Nick Terrell <terrelln@fb.com>,
	 Kan Liang <kan.liang@linux.intel.com>,
	Song Liu <song@kernel.org>,  Sandipan Das <sandipan.das@amd.com>,
	Anshuman Khandual <anshuman.khandual@arm.com>,
	 James Clark <james.clark@arm.com>,
	Liam Howlett <liam.howlett@oracle.com>,
	 Miguel Ojeda <ojeda@kernel.org>, Leo Yan <leo.yan@linaro.org>,
	 German Gomez <german.gomez@arm.com>,
	Ravi Bangoria <ravi.bangoria@amd.com>,
	 Artem Savkov <asavkov@redhat.com>,
	Athira Rajeev <atrajeev@linux.vnet.ibm.com>,
	 Andi Kleen <ak@linux.intel.com>,
	linux-kernel@vger.kernel.org,  linux-perf-users@vger.kernel.org,
	bpf@vger.kernel.org
Subject: Re: [PATCH v2 03/13] perf hist: Add missing puts to hist__account_cycles
Date: Wed, 18 Oct 2023 16:16:11 -0700	[thread overview]
Message-ID: <CAM9d7cg=v9rnPz4cy2yeNZNSCoZ3VReC895gHPTO-emn6XdLXg@mail.gmail.com> (raw)
In-Reply-To: <20231012062359.1616786-4-irogers@google.com>

Hi Ian,

On Wed, Oct 11, 2023 at 11:24 PM Ian Rogers <irogers@google.com> wrote:
>
> Caught using reference count checking on perf top with
> "--call-graph=lbr". After this no memory leaks were detected.
>
> Fixes: 57849998e2cd ("perf report: Add processing for cycle histograms")
> Signed-off-by: Ian Rogers <irogers@google.com>
> ---
>  tools/perf/util/hist.c | 10 +++++++---
>  1 file changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/tools/perf/util/hist.c b/tools/perf/util/hist.c
> index 3dc8a4968beb..ac8c0ef48a7f 100644
> --- a/tools/perf/util/hist.c
> +++ b/tools/perf/util/hist.c
> @@ -2676,8 +2676,6 @@ void hist__account_cycles(struct branch_stack *bs, struct addr_location *al,
>
>         /* If we have branch cycles always annotate them. */
>         if (bs && bs->nr && entries[0].flags.cycles) {
> -               int i;
> -

Seems not necessary.

>                 bi = sample__resolve_bstack(sample, al);

It looks like this increases the refcount for each bi entry and
it didn't put the refcounts.

>                 if (bi) {
>                         struct addr_map_symbol *prev = NULL;
> @@ -2692,7 +2690,7 @@ void hist__account_cycles(struct branch_stack *bs, struct addr_location *al,
>                          * Note that perf stores branches reversed from
>                          * program order!
>                          */
> -                       for (i = bs->nr - 1; i >= 0; i--) {
> +                       for (int i = bs->nr - 1; i >= 0; i--) {
>                                 addr_map_symbol__account_cycles(&bi[i].from,
>                                         nonany_branch_mode ? NULL : prev,
>                                         bi[i].flags.cycles);
> @@ -2701,6 +2699,12 @@ void hist__account_cycles(struct branch_stack *bs, struct addr_location *al,
>                                 if (total_cycles)
>                                         *total_cycles += bi[i].flags.cycles;
>                         }
> +                       for (unsigned int i = 0; i < bs->nr; i++) {

Can we just reuse the int i above?

Thanks,
Namhyung

> +                               map__put(bi[i].to.ms.map);
> +                               maps__put(bi[i].to.ms.maps);
> +                               map__put(bi[i].from.ms.map);
> +                               maps__put(bi[i].from.ms.maps);
> +                       }
>                         free(bi);
>                 }
>         }
> --
> 2.42.0.609.gbb76f46606-goog
>