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From:   Ian Rogers <irogers@google.com>
Date:   Wed, 6 Dec 2023 15:51:58 -0800
Message-ID: <CAP-5=fWGGmQWf7hH8Qqe01YNO3dc0DCDSqa3bHbKMSGioJnyTw@mail.gmail.com>
Subject: Re: [PATCH v5 19/50] perf maps: Do simple merge if given map doesn't overlap
To:     Namhyung Kim <namhyung@kernel.org>
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>,
        Andi Kleen <ak@linux.intel.com>,
        Kajol Jain <kjain@linux.ibm.com>,
        Athira Rajeev <atrajeev@linux.vnet.ibm.com>,
        Huacai Chen <chenhuacai@kernel.org>,
        Masami Hiramatsu <mhiramat@kernel.org>,
        Vincent Whitchurch <vincent.whitchurch@axis.com>,
        "Steinar H. Gunderson" <sesse@google.com>,
        Liam Howlett <liam.howlett@oracle.com>,
        Miguel Ojeda <ojeda@kernel.org>,
        Colin Ian King <colin.i.king@gmail.com>,
        Dmitrii Dolgov <9erthalion6@gmail.com>,
        Yang Jihong <yangjihong1@huawei.com>,
        Ming Wang <wangming01@loongson.cn>,
        James Clark <james.clark@arm.com>,
        K Prateek Nayak <kprateek.nayak@amd.com>,
        Sean Christopherson <seanjc@google.com>,
        Leo Yan <leo.yan@linaro.org>,
        Ravi Bangoria <ravi.bangoria@amd.com>,
        German Gomez <german.gomez@arm.com>,
        Changbin Du <changbin.du@huawei.com>,
        Paolo Bonzini <pbonzini@redhat.com>, Li Dong <lidong@vivo.com>,
        Sandipan Das <sandipan.das@amd.com>,
        liuwenyu <liuwenyu7@huawei.com>, linux-kernel@vger.kernel.org,
        linux-perf-users@vger.kernel.org,
        Guilherme Amadio <amadio@gentoo.org>
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On Mon, Dec 4, 2023 at 4:06=E2=80=AFPM Namhyung Kim <namhyung@kernel.org> w=
rote:
>
> On Mon, Nov 27, 2023 at 2:10=E2=80=AFPM Ian Rogers <irogers@google.com> w=
rote:
> >
> > Simplify merge in for the simple case of a non-overlapping map.
> >
> > Signed-off-by: Ian Rogers <irogers@google.com>
>
> A nitpick below.
>
> > ---
> >  tools/perf/util/maps.c | 11 +++++++++++
> >  1 file changed, 11 insertions(+)
> >
> > diff --git a/tools/perf/util/maps.c b/tools/perf/util/maps.c
> > index 40df08dd9bf3..14e1a169433d 100644
> > --- a/tools/perf/util/maps.c
> > +++ b/tools/perf/util/maps.c
> > @@ -696,9 +696,20 @@ void maps__fixup_end(struct maps *maps)
> >  int maps__merge_in(struct maps *kmaps, struct map *new_map)
> >  {
> >         struct map_rb_node *rb_node;
> > +       struct rb_node *first;
> > +       bool overlaps;
> >         LIST_HEAD(merged);
> >         int err =3D 0;
> >
> > +       down_read(maps__lock(kmaps));
> > +       first =3D first_ending_after(kmaps, new_map);
> > +       overlaps =3D first &&
> > +               map__start(rb_entry(first, struct map_rb_node, rb_node)=
->map) < map__end(new_map);
>
> Can you please break this like below?
>
>     rb_node =3D first ? rb_entry(first, struct map_rb_node, rb_node) : NU=
LL;
>     overlap =3D rb_node && map__start(rb_node->map) < map_end(new_map);

Done in v6.

Thanks,
Ian

> Thanks,
> Namhyung
>
>
> > +       up_read(maps__lock(kmaps));
> > +
> > +       if (!overlaps)
> > +               return maps__insert(kmaps, new_map);
> > +
> >         maps__for_each_entry(kmaps, rb_node) {
> >                 struct map *old_map =3D rb_node->map;
> >
> > --
> > 2.43.0.rc1.413.gea7ed67945-goog
> >