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From: Jiri Olsa <jolsa@redhat.com>
To: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>,
	Arnaldo Carvalho de Melo <acme@kernel.org>,
	lkml <linux-kernel@vger.kernel.org>,
	Peter Zijlstra <a.p.zijlstra@chello.nl>,
	Ingo Molnar <mingo@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	Namhyung Kim <namhyung@kernel.org>,
	Alexander Shishkin <alexander.shishkin@linux.intel.com>,
	Michael Petlan <mpetlan@redhat.com>,
	Song Liu <songliubraving@fb.com>,
	Stephane Eranian <eranian@google.com>,
	Alexey Budankov <alexey.budankov@linux.intel.com>,
	Andi Kleen <ak@linux.intel.com>,
	Adrian Hunter <adrian.hunter@intel.com>
Subject: Re: [PATCH 06/24] perf tools: Add build_id__is_defined function
Date: Tue, 17 Nov 2020 21:53:59 +0100	[thread overview]
Message-ID: <20201117205359.GJ1216482@krava> (raw)
In-Reply-To: <CAP-5=fUrf9Kq3XwKALSZut3M6NXtnJCAMw0Pe2rh8_31a7tX4w@mail.gmail.com>

On Tue, Nov 17, 2020 at 11:00:37AM -0800, Ian Rogers wrote:
> On Tue, Nov 17, 2020 at 3:01 AM Jiri Olsa <jolsa@kernel.org> wrote:
> 
> > Adding build_id__is_defined helper to check build id
> > is defined and is != zero build id.
> >
> > Signed-off-by: Jiri Olsa <jolsa@kernel.org>
> > ---
> >  tools/perf/util/build-id.c | 7 +++++++
> >  tools/perf/util/build-id.h | 1 +
> >  2 files changed, 8 insertions(+)
> >
> > diff --git a/tools/perf/util/build-id.c b/tools/perf/util/build-id.c
> > index 6b410c3d52dc..7d9ecc37849c 100644
> > --- a/tools/perf/util/build-id.c
> > +++ b/tools/perf/util/build-id.c
> > @@ -912,3 +912,10 @@ void build_id__init(struct build_id *bid, const u8
> > *data, size_t size)
> >         memcpy(bid->data, data, size);
> >         bid->size = size;
> >  }
> > +
> > +bool build_id__is_defined(const struct build_id *bid)
> > +{
> > +       static u8 zero[BUILD_ID_SIZE];
> > +
> > +       return bid && bid->size ? memcmp(bid->data, &zero, bid->size) :
> > false;
> >
> 
> Fwiw, I find this method to test for zero a little hard to parse - I'm

heh, it's controversial one, Namhyung commented
on this one in previous version, so I changed it ;-)
  https://lore.kernel.org/lkml/CAM9d7cjjGjTN8sDgLZ1PoQZ-sUXWjnVaNdyOVE1yHxq46PrPkw@mail.gmail.com/


> failing as a C programmer :-) Nit, should zero be const?

right, should be const, will change

thanks,
jirka


  parent reply	other threads:[~2020-11-17 20:54 UTC|newest]

Thread overview: 47+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-17 11:00 [PATCHv2 00/24] perf: Add mmap2 build id support Jiri Olsa
2020-11-17 11:00 ` [PATCH 01/24] bpf: Move stack_map_get_build_id into lib Jiri Olsa
2020-11-17 11:00 ` [PATCH 02/24] bpf: Add size arg to build_id_parse function Jiri Olsa
2020-11-17 11:00 ` [PATCH 03/24] perf: Add build id data in mmap2 event Jiri Olsa
2020-11-17 11:13   ` Peter Zijlstra
2020-11-26 16:55     ` Jiri Olsa
2020-11-17 11:00 ` [PATCH 04/24] tools headers uapi: Sync tools/include/uapi/linux/perf_event.h Jiri Olsa
2020-11-17 11:00 ` [PATCH 05/24] perf tools: Do not swap mmap2 fields in case it contains build id Jiri Olsa
2020-11-17 11:00 ` [PATCH 06/24] perf tools: Add build_id__is_defined function Jiri Olsa
     [not found]   ` <CAP-5=fUrf9Kq3XwKALSZut3M6NXtnJCAMw0Pe2rh8_31a7tX4w@mail.gmail.com>
2020-11-17 20:53     ` Jiri Olsa [this message]
2020-11-17 23:33       ` Arnaldo Carvalho de Melo
2020-11-18  9:35         ` Jiri Olsa
2020-11-17 11:00 ` [PATCH 07/24] perf tools: Add filename__decompress function Jiri Olsa
2020-11-17 11:00 ` [PATCH 08/24] perf tools: Add support to read build id from compressed elf Jiri Olsa
2020-11-17 12:33   ` Arnaldo Carvalho de Melo
2020-11-17 11:00 ` [PATCH 09/24] perf tools: Add check for existing link in buildid dir Jiri Olsa
     [not found]   ` <CAP-5=fVc9i2EXPEqzOEHt5xrxqXiR_58KettKqrR9GJdic4sOQ@mail.gmail.com>
2020-11-18  9:11     ` Jiri Olsa
2020-11-17 11:00 ` [PATCH 10/24] perf tools: Use struct extra_kernel_map in machine__process_kernel_mmap_event Jiri Olsa
2020-11-17 11:00 ` [PATCH 11/24] perf tools: Try to load vmlinux from buildid database Jiri Olsa
2020-11-17 11:00 ` [PATCH 12/24] perf tools: Store build id from mmap2 events Jiri Olsa
2020-11-17 12:38   ` Arnaldo Carvalho de Melo
2020-11-17 14:38     ` Jiri Olsa
2020-11-17 11:00 ` [PATCH 13/24] perf tools: Allow mmap2 event to synthesize kernel image Jiri Olsa
2020-11-17 12:44   ` Arnaldo Carvalho de Melo
2020-11-17 15:16     ` Jiri Olsa
2020-11-17 17:43       ` Arnaldo Carvalho de Melo
2020-11-17 20:45         ` Jiri Olsa
2020-11-17 11:00 ` [PATCH 14/24] perf tools: Allow mmap2 event to synthesize modules Jiri Olsa
2020-11-17 12:46   ` Arnaldo Carvalho de Melo
2020-11-17 11:00 ` [PATCH 15/24] perf tools: Synthesize build id for kernel/modules/tasks Jiri Olsa
2020-11-17 12:47   ` Arnaldo Carvalho de Melo
2020-11-17 11:00 ` [PATCH 16/24] perf tools: Add support to display build id for mmap2 events Jiri Olsa
2020-11-17 11:00 ` [PATCH 17/24] perf tools: Use machine__for_each_dso in perf_session__cache_build_ids Jiri Olsa
2020-11-17 11:00 ` [PATCH 18/24] perf tools: Add __perf_session__cache_build_ids function Jiri Olsa
2020-11-17 11:00 ` [PATCH 19/24] perf tools: Add is_perf_data function Jiri Olsa
2020-11-17 11:00 ` [PATCH 20/24] perf tools: Add build_id_cache__add function Jiri Olsa
2020-11-17 11:00 ` [PATCH 21/24] perf buildid-cache: Add support to add build ids from perf data Jiri Olsa
2020-11-17 12:48   ` Arnaldo Carvalho de Melo
2020-11-17 11:00 ` [PATCH 22/24] perf buildid-cache: Add --debuginfod option Jiri Olsa
2020-11-17 12:49   ` Arnaldo Carvalho de Melo
2020-11-17 11:00 ` [PATCH 23/24] perf buildid-list: Add support for mmap2's buildid events Jiri Olsa
2020-11-17 12:50   ` Arnaldo Carvalho de Melo
2020-11-17 15:21     ` Jiri Olsa
2020-11-17 17:54       ` Arnaldo Carvalho de Melo
2020-11-17 20:50         ` Jiri Olsa
2020-11-17 11:00 ` [PATCH 24/24] perf record: Add --buildid-mmap option to enable mmap's build id Jiri Olsa
  -- strict thread matches above, loose matches on Subject: below --
2020-11-09 21:53 [PATCH 00/24] perf: Add mmap2 build id support Jiri Olsa
2020-11-09 21:53 ` [PATCH 06/24] perf tools: Add build_id__is_defined function Jiri Olsa

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