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profile-manual: Review edits from Robert P. J. Day 

Given the length of the tools sections in the profiling manual,
I'm doing each tool separately so that patches come in
manageable chunks.

(From yocto-docs rev: 9e06ea7c09ca397f7ade7404f9d3fd2dc17da095)

Signed-off-by: Scott Rifenbark <scott.m.rifenbark@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
This commit is contained in:
Robert P. J. Day 2013-11-15 08:47:32 -08:00 committed by Richard Purdie
parent ea8dcadbe5
commit ac3f5a3e78
1 changed files with 12 additions and 12 deletions
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24
documentation/profile-manual/profile-manual-usage.xml
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@ -22,7 +22,7 @@
<para>
Don't let the fact that it's part of the kernel fool you into thinking
that it's only for tracing and profiling the kernel - you can indeed
use it to trace and profile just the kernel , but you can also use it
use it to trace and profile just the kernel, but you can also use it
to profile specific applications separately (with or without kernel
context), and you can also use it to trace and profile the kernel
and all applications on the system simultaneously to gain a system-wide
@ -30,10 +30,10 @@
</para>
<para>
In many ways, it aims to be a superset of all the tracing and profiling
In many ways, perf aims to be a superset of all the tracing and profiling
tools available in Linux today, including all the other tools covered
in this HOWTO. The past couple of years have seen perf subsume a lot
of the functionality of those other tools, and at the same time those
of the functionality of those other tools and, at the same time, those
other tools have removed large portions of their previous functionality
and replaced it with calls to the equivalent functionality now
implemented by the perf subsystem. Extrapolation suggests that at
@ -126,7 +126,7 @@
wget <ulink url='http://downloads.yoctoproject.org/mirror/sources/linux-2.6.19.2.tar.bz2'>http://downloads.yoctoproject.org/mirror/sources/linux-2.6.19.2.tar.bz2</ulink>
</literallayout>
The quickest and easiest way to get some basic overall data about
what's going on for a particular workload it to profile it using
what's going on for a particular workload is to profile it using
'perf stat'. 'perf stat' basically profiles using a few default
counters and displays the summed counts at the end of the run:
<literallayout class='monospaced'>
@ -201,7 +201,7 @@
As our first attempt at profiling this workload, we'll simply
run 'perf record', handing it the workload we want to profile
(everything after 'perf record' and any perf options we hand
it - here none - will be executedin a new shell). perf collects
it - here none - will be executed in a new shell). perf collects
samples until the process exits and records them in a file named
'perf.data' in the current working directory.
<literallayout class='monospaced'>
@ -241,7 +241,7 @@
Notice also that the above report shows an entry for 'busybox',
which is the executable that implements 'wget' in Yocto, but that
instead of a useful function name in that entry, it displays
an not-so-friendly hex value instead. The steps below will show
a not-so-friendly hex value instead. The steps below will show
how to fix that problem.
</para>
@ -308,7 +308,7 @@
</para>
<para>
Notice also that here there's also a case where the a hex value
Notice also that here there's also a case where the hex value
is displayed in the callstack, here in the expanded
sys_clock_gettime() function. Later we'll see it resolve to a
userspace function call in busybox.
@ -367,7 +367,7 @@
<para>
To generate the debug info for the packages in the image, we can
to add dbg-pkgs to EXTRA_IMAGE_FEATURES in local.conf. For example:
add dbg-pkgs to EXTRA_IMAGE_FEATURES in local.conf. For example:
<literallayout class='monospaced'>
EXTRA_IMAGE_FEATURES = "debug-tweaks tools-profile dbg-pkgs"
</literallayout>
@ -462,7 +462,7 @@
The tracing and profiling infrastructure in Linux has become
unified in a way that allows us to use the same tool with a
completely different set of counters, not just the standard
hardware counters that traditionally tools have had to restrict
hardware counters that traditional tools have had to restrict
themselves to (of course the traditional tools can also make use
of the expanded possibilities now available to them, and in some
cases have, as mentioned previously).
@ -828,7 +828,7 @@
</para>
<para>
Luckily, there is general-purpose way to handle such needs,
Luckily, there is a general-purpose way to handle such needs,
called 'programming languages'. Making programming languages
easily available to apply to such problems given the specific
format of data is called a 'programming language binding' for
@ -925,9 +925,9 @@
</literallayout>
Each event handler function in the generated code is modified
to do this. For convenience, we define a common function called
inc_counts() that each handler calls; inc_counts simply tallies
inc_counts() that each handler calls; inc_counts() simply tallies
a count for each event using the 'counts' hash, which is a
specialized has function that does Perl-like autovivification, a
specialized hash function that does Perl-like autovivification, a
capability that's extremely useful for kinds of multi-level
aggregation commonly used in processing traces (see perf's
documentation on the Python language binding for details):