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Optimizing Linux® Performance: A Hands-On Guide to Linux® Performance ToolsBy
Table of Contents
| Index
The first comprehensive, expert guide for end-to-end Linux
application optimization
Learn to choose the right toolsand use them together to
solve real problems in real production environmentsSuperior application performance is more crucial than
everand in today''s complex production environments, it''s
tougher to ensure, too. If you use Linux, you have extraordinary
advantages: complete source code access, plus an exceptional array
of optimization tools. But the tools are scattered across the
Internet. Many are poorly documented. And few experts know how to
use them together to solve real problems. Now, one of those experts
has written the definitive Linux tuning primer for every
professional: Optimizing Linux® Performance.Renowned Linux benchmarking specialist Phillip Ezolt introduces
each of today''s most important Linux optimization tools, showing
how they fit into a proven methodology for perfecting overall
application performance. Using realistic examples, Ezolt shows
developers how to pinpoint exact lines of source code that are
impacting performance. He teaches sysadmins and application
developers how to rapidly drill down to specific bottlenecks, so
they can implement solutions more quickly. You''ll discover how
to:
Identify bottlenecks even if you''re not familiar with the
underlying system
Find and choose the right performance tools for any
problem
Recognize the meaning of the events you''re measuring
Optimize system CPU, user CPU, memory, network I/O, and disk
I/Oand understand their interrelationships
Fix CPU-bound, latency-sensitive, and I/O-bound applications,
through case studies you can easily adapt to your own
environmentInstall and use oprofile, the advanced systemwide profiler for
Linux systemsIf you''re new to tuning, Ezolt gives you a clear and practical
introduction to all the principles and strategies you''ll need. If
you''re migrating to Linux, you''ll quickly master Linux equivalents
to the tools and techniques you already know. Whatever your
background or environment, this book can help you improve the
performance of all your Linux applicationsincreasing
business value and user satisfaction at the same time.
11.11. Chapter Summary
In this chapter, we determined why a particular component of an application had high latency (pop-up menus in nautilus). We figured out how to automate the creation of the pop-up menus (xautomation) and extend the amount of time that nautilus spent creating pop-up means (100 iterations). We used oprofile to figure out in which function nautilus was spending all of its time. We then used ltrace and gdb to determine which shared library calls were responsible for making all the calls. After we figured out which library calls were high cost, we tried to reduce or limit the number of times they were called. In this case, we stored a pointer to a new menu when it was allocated and used it later to avoid unneeded reallocations. We created a proposed patch and then ran our performance test against it to see whether performance improved. Performance improved, and functionality did not appear to be affected. The next step is to submit the patch to the nautilus developers for comment. Whereas this chapter focused on optimizing a single application's latency, the next chapter presents a performance hunt that concentrates on solving a system-level performance problem. This type of hunt can often involve investigating many different areas of the system, including hardware (disk, network, and memory) and software (applications, shared libraries, and the Linux kernel).
