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From: Ian Rogers <irogers@google.com>
Date: Wed, 5 Jun 2024 16:54:40 -0700
Message-ID: <CAP-5=fXJrGWpOo9B9V-T9K2fkQBhgL6edo-c039nCn=Y7FxSEg@mail.gmail.com>
Subject: Re: [PATCH v1 0/3] Fix and improve __maps__fixup_overlap_and_insert
To: "Steinar H . Gunderson" <sesse@google.com>, Peter Zijlstra <peterz@infradead.org>, 
	Ingo Molnar <mingo@redhat.com>, Arnaldo Carvalho de Melo <acme@kernel.org>, Namhyung Kim <namhyung@kernel.org>, 
	Mark Rutland <mark.rutland@arm.com>, 
	Alexander Shishkin <alexander.shishkin@linux.intel.com>, Jiri Olsa <jolsa@kernel.org>, 
	Ian Rogers <irogers@google.com>, Adrian Hunter <adrian.hunter@intel.com>, 
	Kan Liang <kan.liang@linux.intel.com>, linux-perf-users@vger.kernel.org, 
	linux-kernel@vger.kernel.org
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On Tue, May 21, 2024 at 9:51=E2=80=AFAM Ian Rogers <irogers@google.com> wro=
te:
>
> Fix latent unlikely bugs in __maps__fixup_overlap_and_insert.
>
> Improve __maps__fixup_overlap_and_insert's performance 21x in the case
> of overlapping mmaps. sesse@google.com reported slowness opening
> perf.data files from chromium where the files contained a large number
> of overlapping mappings. Improve this case primarily by avoiding
> unnecessary sorting.
>
> Unscientific timing data processing a perf.data file with overlapping
> mmap events from chromium:
>
> Before:
> real    0m9.856s
> user    0m9.637s
> sys     0m0.204s
>
> After:
> real    0m0.675s
> user    0m0.454s
> sys     0m0.196s
>
> Tested with address/leak sanitizer, invariant checks and validating
> the before and after output are identical.
>
> Ian Rogers (3):
>   perf maps: Fix use after free in __maps__fixup_overlap_and_insert
>   perf maps: Reduce sorting for overlapping mappings
>   perf maps: Add/use a sorted insert for fixup overlap and insert

Ping. Thanks,
Ian

>  tools/perf/util/maps.c | 113 +++++++++++++++++++++++++++++++++--------
>  1 file changed, 92 insertions(+), 21 deletions(-)
>
> --
> 2.45.0.rc1.225.g2a3ae87e7f-goog
>