All of lore.kernel.org
 help / color / mirror / Atom feed
From: Andi Kleen <ak@linux.intel.com>
To: Ingo Molnar <mingo@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>,
	linux-kernel@vger.kernel.org,
	Stephane Eranian <eranian@google.com>,
	Arnaldo Carvalho de Melo <acme@redhat.com>
Subject: Re: [PATCH 10/11] perf tools: Add probing for udev86 library
Date: Wed, 30 Mar 2016 07:42:19 -0700	[thread overview]
Message-ID: <20160330144219.GC9083@tassilo.jf.intel.com> (raw)
In-Reply-To: <20160330104326.GB4681@gmail.com>

On Wed, Mar 30, 2016 at 12:43:27PM +0200, Ingo Molnar wrote:
> 
> * Arnaldo Carvalho de Melo <acme@kernel.org> wrote:
> 
> > From: Andi Kleen <ak@linux.intel.com>
> > 
> > Add autoprobing for the udev86 disassembler library.
> 
> So the typo in the title is confusing, what is 'udev86'?

Agreed, it's confusing. It was meant to be udis86.

http://udis86.sourceforge.net

The next patch that uses it had the URL too, but that didn't make it
when this patch was split off.

> 
> Also, this library does not seem to be available on stock Ubuntu. We should not be 
> adding library dependencies that cannot be resolved on major distros:
> 
>  ...                     get_cpuid: [ on  ]
>  ...                           bpf: [ on  ]
>  ...                        udis86: [ OFF ]

It's a chicken'n'egg problem. Likely when perf needs it they will add it soon.
For now it's fairly easy to install manually.

Using a real disassembler in perf has a lot of advantages over objdump. It allows
full instruction traces with PT, which is useful for debugging. It also
allows hot path analysis of branch mispredictions and automatic micro benchmarks
using LBRs (implemented inn https://lkml.org/lkml/2016/3/28/331). Possibly
more in the future.

-Andi

  parent reply	other threads:[~2016-03-30 14:42 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-03-29 23:41 [GIT PULL 00/11] perf/core improvements and fixes Arnaldo Carvalho de Melo
2016-03-29 23:41 ` [PATCH 01/11] perf mem: Add -U/-K (--all-user/--all-kernel) options Arnaldo Carvalho de Melo
2016-03-29 23:41 ` [PATCH 02/11] perf tools: Make hists__collapse_insert_entry static Arnaldo Carvalho de Melo
2016-03-29 23:41 ` [PATCH 03/11] perf tools: Make -f/--force option documentation consistent across tools Arnaldo Carvalho de Melo
2016-03-29 23:41 ` [PATCH 04/11] perf tests: Add test to check for event times Arnaldo Carvalho de Melo
2016-03-29 23:41 ` [PATCH 05/11] perf config: Remove duplicated set_buildid_dir calls Arnaldo Carvalho de Melo
2016-03-29 23:41 ` [PATCH 06/11] perf config: Rework buildid_dir_command_config to perf_buildid_config Arnaldo Carvalho de Melo
2016-03-29 23:41 ` [PATCH 07/11] perf config: Rename 'v' to 'home' in set_buildid_dir() Arnaldo Carvalho de Melo
2016-03-29 23:41 ` [PATCH 08/11] perf script perl: Perl scripts now get a backtrace, like the python ones Arnaldo Carvalho de Melo
2016-03-29 23:41 ` [PATCH 09/11] perf tools: Add support for skipping itrace instructions Arnaldo Carvalho de Melo
2016-03-29 23:41 ` [PATCH 10/11] perf tools: Add probing for udev86 library Arnaldo Carvalho de Melo
2016-03-30 10:43   ` Ingo Molnar
2016-03-30 13:36     ` Arnaldo Carvalho de Melo
2016-03-30 13:52       ` Ingo Molnar
2016-03-30 14:10         ` Arnaldo Carvalho de Melo
2016-03-30 14:47           ` Arnaldo Carvalho de Melo
2016-03-31  6:34             ` Ingo Molnar
2016-03-30 15:08         ` Andi Kleen
2016-03-31  6:49           ` Ingo Molnar
2016-03-30 14:42     ` Andi Kleen [this message]
2016-03-29 23:41 ` [PATCH 11/11] perf script: Add support for printing assembler Arnaldo Carvalho de Melo

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20160330144219.GC9083@tassilo.jf.intel.com \
    --to=ak@linux.intel.com \
    --cc=acme@kernel.org \
    --cc=acme@redhat.com \
    --cc=eranian@google.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.