https://github.com/fabienarcellier/perfug-deep-into-your-application

Start to profile any applications on your linux system that you being either dev or ops
https://github.com/fabienarcellier/perfug-deep-into-your-application

Last synced: 25 days ago
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Start to profile any applications on your linux system that you being either dev or ops

• Host: GitHub
• URL: https://github.com/fabienarcellier/perfug-deep-into-your-application
• Owner: FabienArcellier
• Created: 2015-09-19T09:50:22.000Z (over 9 years ago)
• Default Branch: master
• Last Pushed: 2015-10-10T09:22:58.000Z (about 9 years ago)
• Last Synced: 2023-03-10T21:48:01.999Z (almost 2 years ago)
• Language: CSS
• Homepage: http://fabienarcellier.github.io/Perfug-Deep-into-your-application
• Size: 3.17 MB
• Stars: 0
• Watchers: 2
• Forks: 1
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

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README

        
Introduction

=============

Codes & slides for the presentation done to the 24th performance user group

at Paris the 17/09/2015.

# [Slides](http://fabienarcellier.github.io/Perfug-Deep-into-your-application/slides/index.html)

I recommand looking at the [presentation](http://fabienarcellier.github.io/Perfug-Deep-into-your-application/slides/index.html) first before playing with commands

below.

[Link to the website](http://fabienarcellier.github.io/Perfug-Deep-into-your-application)

Notes

=====

Example - Calculus on simple matrix

------------------------------------

		cd src/02-matrix

		make build

		time valgrind --tool=callgrind --simulate-cache=yes --dump-instr=yes --collect-jumps=yes ./app 100 100

Look at symbol table

--------------------

		cd src/00-empty

		make build

		readelf -s ./app;

		readelf -s /lib/x86_64-linux-gnu/libc.so.6 | grep malloc

		# Strip effect on the symbol table

		strip ./app

		readelf -s ./app;

Profiling Callgrind

---------------------

		cd src/02-matrix

		make build

		# Profiling with callgrind for 100 * 100 matrix

		time valgrind --tool=callgrind --simulate-cache=yes --dump-instr=yes --collect-jumps=yes ./app 100 100

		# Perf impact of callgrind

		time ./app 100 100

Thread dump on Native application - Gstack

--------------------------------------------

		cd ~/sources/memcached

		sudo -s

Bash function to generate thread dump for native application as you

can do with jstack

		gstack() {

		  tmp=$(tempfile)

		  echo thread apply all bt >"$tmp"

		  gdb -batch -nx -q -x "$tmp" -p "$1"

		  rm -f "$tmp"

		}

Use it

		./memcached &

		while sleep 1; do gstack @pid@ ; done

Perf - Some commands

---------------------

Get a list of avaible counters.

    perf list

Get an overview of counters for an application

    perf stat ./app

Perf - Impact on performance

-----------------------------

		time ./app 500 500

		time perf record -g ./app 500 500

Memcached - Symbol table

--------------------------

		cd ~/sources/memcached

		readelf -s ./memcached

Generate flamegraph from gdb stacktraces

------------------------------------------

		cd ~/sources/memcached

		./memcached &

		php src/03-memcache-php/memcache-set.php

		while sleep 0.1; do gstack 8748; done > stack.txt

		cat stack.txt | stackcollapse-gdb.pl | flamegraph.pl > gdb_graph.svg

MEMCACHE - PROFILING WITH PERF

-------------------------------

		cd ~/sources/memcached

		perf record -g ./memcached

		php src/03-memcache-php/memcache-set.php

		perf report

		Warning to /proc/sys/kernel/kptr_restrict

MEMCACHED - PROFILING CPU CYCLE WITH PERF - WITH KERNEL STACKTRACE

-------------------------------------------------------------------

		./memcached &

		sudo perf record -a -g -p @pid@

		php src/03-memcache-php/memcache-set.php

		perf report