Profile the build system

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Revision as of 21:50, 18 September 2008 by Cbishop2 (talk | contribs) (Project Data)
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Name of Project

Profile the build system


It's a well known fact that it takes longer to build on Windows than on a comparable Linux or Mac machine. We don't know exactly why, however. There have been many theories, but no real data. Profiling the build system would allow us to figure out where all of the time is being spent. The best place to start might be by adding some profiling to GNU Make, to figure out which targets in our makefiles take the most time. From there, depending on the results, profiling could be added to other parts of the build system to narrow down specific bottlenecks.


  1. - did something similar

Resources: ted


Project Contributor(s)

Project Details

  • Collect Data
    • Get build time info from others
      • Build From Scratch, Rebuild with no changes, using/not using -j4 option, hardware info (RAM, CPU, RPM)

  • The -j4 option is used in the .mozconfig file
  • -j specifies how many concurrent jobs you can run, so for some parts of the tree you get more makes going at once
    • mk_add_options MOZ_MAKE_FLAGS=-j4

Project Data

  • Please feel free to fill in the table to help me collect more data
  • you can time your build by adding the "time" command in front of your build command like so:
    • time make -f build
Build Time Data
Build From Scratch


Rebuilt No Changes


with -j# RAM (GB) CPU (GHz) HD (rpm) OS User Mozconfig
0:55:05 0:20:17 5 4 GB 2.0 Duo 7200 Vista Business Patrick
0:59:00 0:21:00 4 4 GB 2.0 Duo 7200 Vista Business Patrick
1:15:25 0:21:22 N/A 4 GB 2.0 Duo 7200 Vista Business Patrick
1:03:00 N/A 1 GB 1.6 Duo XP Media Tony
0:50:00 N/A 2.5 GB 1.6 AMD TurionX2 XP Professional Zaid
1:17:44 - 2 1.5 GB 1.8 AMD Mobile Sempron 5400 Vista Business (32-bit) Nino
0:24:15 0:01:07 N/A 2 GB 2.66 Duo 7200 Ubuntu 8.04 (64-bit) Jason
0:15:12 0:01:04 4 2 GB 2.66 Duo 7200 Ubuntu 8.04 (64-bit) Jason
0:43:14 - - 2 GB 1.80 AMD Mobile Sempron 5400 Ubuntu 8.04 (32-bit) Aaron T
real 0:29:13
user 0:11:26
sys 0:03:47
real 0:05:8
user 0:04:47
sys 0:01:43
5 1 GB 2.0 Duo ( OC'd to 2.41 ) 7200 Windows XP Professional ( 32-bit) Chris Bishop
. $topsrcdir/browser/config/mozconfig
mk_add_options MOZ_OBJDIR=@TOPSRCDIR@/ff-opt
mk_add_options MOZ_MAKE_FLAGS=-j5
ac_add_options --disable-tests

Project News / Updates

09/18/2008 -

  • Use time command to time build time
    • ie. time make -f build
  • Start collecting data

09/17/2008 -

  • Built the first time in 1h 20m
  • Rebuilt second time in 35m with all apps off
  • Talked with Shaver and directed me to thread on shrinking build time
    • Thread talked about /MP command for building in VS -> not useful in my case
  • Dave's suggestion
    • Understand what each part of the build is taking
    • Collect win32 build times from colleagues

09/16/2008 -

  • Talked with Ted Mielczarek, briefly discussed about where to start and how to approach this project.
    • Start by timing how long each make file is
    • Identify which make file takes a long time

09/15/2008 -

  • Created Project page for this project.