¶ Chromium Summer of Code

¶ Proposal

• Project Forging an efficient Cr for Linux for Chromium
• Proposal cr-power-proposal
• Mentor Dean McNamee

This project will look towards making Chromium on Linux a pleasant experience. Ensuring the browser starts as fast as possible, doesn't leak memory, stays asleep when it's not busy, and does it's work as efficiently as possible will the goals.

I will look to test Chromium on smaller machines, such as netbooks using Intel's Atom and the Beagleboard using ARM's Cortex-A8, measuring power usage of the machines to see if the browser effects this as the code evolves.

I will also work on profiling the browser using the tools available on Linux, such as powertop, Oprofile and Valgrind and presenting these results as hints for developers.

I am a student at the University of Adelaide studying for my Electrical and Electronic (Computer Systems) Engineering degree. I was a participant in the 2007 Summer of Code where, among other things, I worked for the OLPC project on a power measurement system for the XO-1 laptop.

I have a strong interest in a embedded systems such as ARM, as well as understanding how software interacts with our computers from the scheduling of tasks by the kernel, down through the usage of cache and dispatch of instructions to the execution units in the processor.

¶ Project Plan

¶ Tasks

¶ Power measurement

• Build Chromium on ARM

  • Ubuntu has an ARM port

    • I have it running under QEMU
    • TODO: running on beagleboard

  • Patches for ARM have been comitted to the tree

    • 99337
    • 100352
    • 99337

  • Building native is the way to go
  • Cross toolchains I have

    • crosstool-ng
    • android
    • openembedded

  • TODO: learn how to build Cr for ARM

• Chromium on Atom

  • TODO: Look at -march=atom

    • svn://gcc.gnu.org/svn/gcc/branches/ix86/atom
    • Atom pipeline patch

• Chromium on XO 1.5

  • The XO 1.5 will be a Via C7 CPU
  • It will have the tinderbox similar to gen1

    • Email from Wad
    • gen1 power block diagram
    • gen1.5 power block diagram

  • TODO: Ask OLPC for a board

• Power measurement

  • Kill-o-watt like device

    • jaycar.com.au Aussie version
    • -can't do automatic instrumentation, logging, due to 230V
    • +simple

  • Other side of the power pack

    • +low voltage, can measure using arduino
    • -have to chop up power cord

¶ Profiling

• Valgrind

  • TODO: find "vagrind bot" for chrome
  • TODO: ask if there are tasks I could take on to help

• traceline

  • src/tools/traceline
  • Very cool piece of code
  • Downside is it's quite windows specific
  • TODO: port traceline to Linux?

• sp-startup-time

  • Uses LD_PRELOAD hacks to intercept some gtk calls and time gtk startup
  • Written by Nokia for maemo
  • http://maemo.org/development/tools/doc/diablo/sp-startup-time/
  • SpStartupTime for an example of output. This only shows time to start
  • TODO: get full stats output

• oprofile

  • Shows how much processor time are spent in what functions
  • Doesn't give a timeline like traceline, can't tell what spawns what, and where time is spent
  • Some logs taken, highly dependant on what is happening in the browser, eg:

    • browsing+scrolling gmail showed lots of time spent in skia
    • running the gravity demo from chromeexperiments.com showed lots of time in v8.

  • TODO: Work out what meaningful data can be taken from oprofile

    • Running a few well-chosen tests?

¶ Misc

• TODO: submit a patch!

¶ Timeline

TODO

• Bonding period
• Coding peroid