Re: [PATCHSET 00/16] perf top: Add multi-thread support (v1)

From	David Ahern <dsahern@gmail.com>
Newsgroups	linux.kernel
Subject	Re: [PATCHSET 00/16] perf top: Add multi-thread support (v1)
Date	2015-12-14 16:00 +0100
Message-ID	<qFCLw-7vq-29@gated-at.bofh.it> (permalink)
References	(2 earlier) <qE55f-3L0-3@gated-at.bofh.it> <qEr5L-1BY-11@gated-at.bofh.it> <qExuy-69x-11@gated-at.bofh.it> <qFxCa-4ar-15@gated-at.bofh.it> <qFxLP-4dP-17@gated-at.bofh.it>
Organization	linux.* mail to news gateway

Show all headers | View raw

On 12/14/15 2:38 AM, Ingo Molnar wrote:
>
>> And in an unrelated note, I absolutely detest --buildid being the
>> default, it makes perf-record blow chunks.

Yes, a .debug directory that gets bloated fast and being a dot-directory 
is off the primary radar. I forget about it and too often forget to add 
the option to disable it.

>
> So I'd absolutely _love_ to split up the singular perf.data into a hierarchy of
> files in a .perf directory, with a structure like this (4-core system):
>
> 	.perf/cmdline
> 	.perf/features
> 	.perf/evlist
> 	.perf/ring_buffers/cpu0/raw.trace
> 	.perf/ring_buffers/cpu1/raw.trace
> 	.perf/ring_buffers/cpu2/raw.trace
> 	.perf/ring_buffers/cpu3/raw.trace
> 	...

On a related note why a .perf directory?

>
> I.e. the current single file format of perf.data would be split up into individual
> files. Each CPU would get its own trace file output - any sorting and ordering
> would be done afterwards. 'perf record' itself would never by default have to do
> any of that, it's a pure recording session.
>
> 'perf archive' would still create a single file to make transport between machines
> easy.
>
> perf.data.old would be replaced by a .perf.old directory or so.
>
> Debugging would be easier too I think, as there's no complex perf data format
> anymore, it's all in individual (typically text, or binary dump) files in the
> .perf directory.
>
> This would solve all the scalability problems - and would make the format more
> extensible and generally more accessible as well.
>
> What do you think?

Big change to user experience.

I realize perf-archive has been around since I started using perf in 
mid-2010, but I for one never use it. I suspect it is not widely used 
(definitely not in the circles I have been involved and helped with 
perf), so suddenly requiring it is a change in user experience.

The only 2 files on the system I pull off the box are kallsyms and 
perf.data. Most of the systems where I use perf have limited symbols and 
there is nothing in .debug I need to pull of the box.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Thread

Re: [PATCHSET 00/16] perf top: Add multi-thread support (v1) Peter Zijlstra <peterz@infradead.org> - 2015-12-14 10:30 +0100
  Re: [PATCHSET 00/16] perf top: Add multi-thread support (v1) Ingo Molnar <mingo@kernel.org> - 2015-12-14 10:40 +0100
    Re: [PATCHSET 00/16] perf top: Add multi-thread support (v1) David Ahern <dsahern@gmail.com> - 2015-12-14 16:00 +0100
      Re: [PATCHSET 00/16] perf top: Add multi-thread support (v1) Arnaldo Carvalho de Melo <acme@kernel.org> - 2015-12-14 17:30 +0100
        Re: [PATCHSET 00/16] perf top: Add multi-thread support (v1) Peter Zijlstra <peterz@infradead.org> - 2015-12-14 17:50 +0100
          Re: [PATCHSET 00/16] perf top: Add multi-thread support (v1) Arnaldo Carvalho de Melo <acme@kernel.org> - 2015-12-14 19:00 +0100
    Re: [PATCHSET 00/16] perf top: Add multi-thread support (v1) Namhyung Kim <namhyung@kernel.org> - 2015-12-14 17:40 +0100
      Re: [PATCHSET 00/16] perf top: Add multi-thread support (v1) Peter Zijlstra <peterz@infradead.org> - 2015-12-14 18:00 +0100
        Re: [PATCHSET 00/16] perf top: Add multi-thread support (v1) Namhyung Kim <namhyung@kernel.org> - 2015-12-14 18:20 +0100
  Re: [PATCHSET 00/16] perf top: Add multi-thread support (v1) David Ahern <dsahern@gmail.com> - 2015-12-14 15:50 +0100
    Re: [PATCHSET 00/16] perf top: Add multi-thread support (v1) Namhyung Kim <namhyung@kernel.org> - 2015-12-14 18:10 +0100
      Re: [PATCHSET 00/16] perf top: Add multi-thread support (v1) Arnaldo Carvalho de Melo <acme@kernel.org> - 2015-12-14 19:00 +0100
  Re: [PATCHSET 00/16] perf top: Add multi-thread support (v1) Namhyung Kim <namhyung@kernel.org> - 2015-12-14 17:30 +0100
    Re: [PATCHSET 00/16] perf top: Add multi-thread support (v1) Peter Zijlstra <peterz@infradead.org> - 2015-12-14 17:50 +0100

csiph-web