Winter 2017 SPO600 Weekly Schedule
This is the schedule and main index page for the SPO600 Software Portability and Optimization course for Winter 2017.
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This page contains information for a previous version of the course. It will be updated for Winter 2017.
- Previous semester: Winter 2016 SPO600 Weekly Schedule.
Schedule Summary Table
This is a summary/index table. Please follow the links in each cell for additional detail which will be added below as the course proceeds -- especially for the Deliverables column.
Evaluation
| Category | Percentage | Evaluation Dates |
|---|---|---|
| Communication | 20% | 5% each: End of January, end of February, end of March, end of course. |
| Quizzes | 10% | May be held during any class, usually at the start of class. A minimum of 5 one-page quizzes will be given. No make-up/retake option is offered if you miss a quiz. Lowest 3 scores will not be counted. |
| Labs | 10% | See deliverables column above. All labs must be submitted by April 21. |
| Project work | 60% | 3 stages: 15% (March 29) / 20% (April 10) / 25% (April 21) |
Week 1
Tuesday (Jan 12)
Introduction to the Problems
Porting and Portability
- Most software is written in a high-level language which can be compiled into machine code for a specific computer architecture. In many cases, this code can be compiled for multiple architectures. However, there is a lot of existing code that contains some architecture-specific code fragments written in Assembly Language (or, in some cases, machine-specific high-level code).
- Reasons for writing code in Assembly Langauge include:
- Performance
- Atomic Operations
- Direct access to hardware features, e.g., CPUID registers
- Most of the historical reasons for including assembler are no longer valid. Modern compilers can out-perform most hand-optimized assembly code, atomic operations can be handled by libraries or compiler intrinsics, and most hardware access should be performed through the operating system or appropriate libraries.
- A new architecture has appeared: Aarch64, which is part of ARMv8. This is the first new computer architecture to appear in several years (at least, the first mainstream computer architecture).
- At this point, most key open source software (the software typically present in a Linux distribution such as Ubuntu or Fedora, for example) now runs on AArch64. However, it may not run as well as on older architectures (such as x86_64).
Benchmarking and Profiling
Benchmarking involves testing software performance under controlled conditions so that the performance can be compared to other software, the same software operating on other types of computers, or so that the impact of a change to the software can be gauged.
Profiling is the process of analyzing software performance on finer scale, determining resource usage per program part (typically per function/method). This can identify software bottlenecks and potential targets for optimization.
Optimization
Optimization is the process of evaluating different ways that software can be written or built and selecting the option that has the best performance tradeoffs.
Optimization may involve substituting software algorithms, altering the sequence of operations, using architecture-specific code, or altering the build process. It is important to ensure that the optimized software produces correct results and does not cause an unacceptable performance regression for other use-cases, system configurations, operating systems, or architectures.
The definition of "performance" varies according to the target system and the operating goals. For example, in some contexts, low memory or storage usage is important; in other cases, fast operation; and in other cases, low CPU utilization or long battery life may be the most important factor. It is often possible to trade off performance in one area for another; using a lookup table, for example, can reduce CPU utilization and improve battery life in some algorithms, in return for increased memory consumption.
Most advanced compilers perform some level of optimization, and the options selected for compilation can have a significant effect on the trade-offs made by the compiler, affecting memory usage, execution speed, executable size, power consumption, and debuggability.
Build Process
Building software is a complex task that many developers gloss over. The simple act of compiling a program invokes a process with five or more stages, including pre-proccessing, compiling, optimizing, assembling, and linking. However, a complex software system will have hundreds or even thousands of source files, as well as dozens or hundreds of build configuration options, auto configuration scripts (cmake, autotools), build scripts (such as Makefiles) to coordinate the process, test suites, and more.
The build process varies significantly between software packages. Most software distribution projects (including Linux distributions such as Ubuntu and Fedora) use a packaging system that further wraps the build process in a standardized script format, so that different software packages can be built using a consistent process.
In order to get consistent and comparable benchmark results, you need to ensure that the software is being built in a consistent way. Altering the build process is one way of optimizing software.
Note that the build time for a complex package can range up to hours or even days!
General Course Information
- Course resources are linked from the CDOT wiki, starting at http://zenit.senecac.on.ca/wiki/index.php/SPO600 (Quick find: This page will usually be Google's top result for a search on "SPO600").
- Coursework is submitted by blogging.
- Quizzes will be short (1 page) and will be held without announcement at any time. Your lowest three quiz scores will not be counted, so do not worry if you miss one or two.
- Course marks (see Weekly Schedule for dates):
- 60% - Project Deliverables
- 20% - Communication (Blog and Wiki writing)
- 20% - Labs and Quizzes (10% labs - completed/not completed; 10% for quizzes - lowest 3 scores not counted)
- All classes will be held in an Active Learning Classroom -- you are encouraged to bring your own laptop to class. If you do not have a laptop, consider signing one out of the Learning Commons for class, or using a smartphone with an HDMI adapter.
- For more course information, refer to the SPO600 Weekly Schedule (this page), the Course Outline, and SPO600 Course Policies.
- Optional: You can participate in the Linaro Code Porting/Optimization contest. For details, see the YouTube video of Jon "maddog" Hall and Steve Mcintyre at Linaro Connect USA 2013.
Discussion of how open source communities work
- Background for the Code Review Lab (Lab 1).
Friday (Jan 15)
- Overview of the Build and Release Process
- Working with Code
- Getting Code
- In a tarball
- From git
- Git basics
- Working with other version control systems
- Getting and Installing Build Dependencies
- Required tools
- Required libraries, headers, and modules
- Building the Code
- Configuration tools (autotools, cmake)
- Make
- The compiler toolchain
- Preprocessor
- Compiler
- Assembler
- Linker
- Debug vs. Non-debug/Stripped binaries
- Installation Scripts
- Getting Code
- Looking at How Distributions Package the Code
- Using fedpkg
- Code Building Lab (Lab 2) as homework
Week 1 Deliverables
- Course setup:
- Set up your SPO600 Communication Tools - in particular, set up a blog and add it to Planet CDOT (via the Planet CDOT Feed List).
- Add yourself to the Winter 2016 SPO600 Participants page (leave the projects columns blank).
- Generate a pair of keys for SSH and email the public key to your professor.
- Sign and return the Open Source Professional Option Student Agreement.
- Complete Labs
- Code Review Lab (Lab 1) (Due end of week 2)
- Code Building Lab (Lab 2) (Due end of week 1)
- Optional (recommended): Set up a personal Fedora system.
- Optional (recommended): Purchase an AArch64 development board (such as a 96Boards HiKey).
Week 2
Tuesday (Jan 19)
- Computer Architecture overview (see also the Computer Architecture Category)
Friday (Jan 22)
- Assembly language lab (lab 3)
Week 2 Deliverables
- Blog your conclusion to the Code Review Lab (Lab 1)
Week 3
Tuesday (Jan 26)
- Continue work on the Assembly language lab (lab 3)
Friday (Jan 29)
- Compiled C lab (lab 4)
Week 3 Deliverables
- Blog about your Assembly language lab (lab 3).
- Blog about your Compiled C lab (lab 4) experience and results. Consider the optimizations and transformations that the compiler performed.
- Remember that these posts (as all of your blog posts) will be marked both for communication (clarity, quality of writing (including grammar and spelling), formatting, use of links, completeness) and for content (lab completion and results). Your posts should contain both factual results as well as your reflections on the meaning of those results, the experience of performing the lab, and what you have learned.
Reminder: Blogs will be marked as they stand at the end of the month (Sunday).
Week 4
Tuesday (Feb 2)
Software Optimization
- Compiler Optimizations
- Algorithm Selection
Friday (Feb 5)
- Algorithm Selection Lab (Lab 6)
Week 4 Deliverables
- Blog about your Lab 5 results.
Week 5
Tuesday (Feb 9)
- Finish the Algorithm Selection Lab
- Discussion of Benchmarking Challenges
- Introduction to Vector Processing/SIMD
Friday (Feb 12)
- Vectorization Lab (Lab 6)
Week 5 Deliverables
- Blog your results for the Algorithm Selection Lab (Lab 5)
- Blog your results for the Vectorization Lab (Lab 6)
- For each of the above, be sure to include links to your code, detailed results, and your reflection on the lab.
Week 6
Tuesday (Feb 16)
- Discussion of Memory Architecture
Friday (Feb 19)
- Inline Assembly Language -- often used for:
- Implementing a memory barrier
- Performing an Atomic Operation
- Gaining performance (by accessing processor features not exposed by the high-level language being used (C, C++, ...))
- Inline Assembler Lab (Lab 7)
Week 6 Deliverables
- Blog your Lab 7 results.
Week 7
Tuesday (Feb 23)
- Discussion of Course Presentation assignment
Friday (Feb 26)
- Discussion of the Course Project
Week 7 Deliverables
- Blog about your selected Presentation and Project topics.
Week 8
Connect - No classes.
Week 8 Deliverables
- Prepare for your Presentation
- Work on your Project
- Blog about what you're doing!
Week 9
Tuesday (Mar 14)
Friday (Mar 18)
Week 9 Deliverables
- Blog about your Presentation, incorporating any discussion or feedback during the presentation.
Week 10
Tuesday (Mar 22)
- Course Project - Stage I Updates
Week 10 Deliverables
- Blog your Stage I Updates. Important! - this will be used to assign your Stage I project mark! Include:
- Which software package you are working on
- Your experience building the software "out of the box" on x86_64 and AArch64 platforms
- Baseline results (performance)
- Which area of the software you will be working on and which approach you are going to take to optimizing the software...
- Improving the Build Instructions (e.g., compiler options), OR
- Changing the Software (substituting a different algorithm, or refactoring for better compiler optimization e.g., auto-vectorization), OR
- Adding Platform-Specific code for AArch64
Week 11
Tuesday (Mar 29)
- Discussion & Hack Session
Thursday (Mar 31)
Reminder: Special Event: Leadership Lunch with Mike Shaver
Friday (Apr 1)
- Discussion & Hack Session
Week 11 Deliverables
- Blog about your project work.
Week 12
Tuesday (Apr 5)
- Discussion & Hack Session
Friday (Apr 8)
- Project Stage II Updates
Week 12 Deliverables
- Blog your Stage II Project Updates by Midnight, Sunday, Apr 10. Note that this will be used for your Stage II project mark (20%).
Week 13
Tuesday (Apr 12)
- Wrap-Up Discussion
Friday (Apr 15)
- Stage III Project Updates
Week 13 Deliverables
- Blog your Stage III Project Updates by Midnight on Thursday, April 21.
- Complete ALL your blogging for this course by Midnight on Thursday, April 21. Make sure that you have included all of the labs, your presentation, and your project work. Remember that there should be at least 1-2 posts per week. Your blogging from April 1-April 21 will be used for your April communication mark.