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a/b test mallocs against your memory footprint
The other day at Kickball Labs we were discussing whether linking Ruby against tcmalloc (or ptmalloc3, nedmalloc, or any other malloc) would have any noticeable effect on application latency. After...
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5 Things You Don’t Know About User IDs That Will Destroy You
*nix user and group IDs are complicated, confusing, and often misused. Look at this code snippet from the popular Ruby project, Starling: def drop_privileges Process.egid = options[:group] if...
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Fix a bug in Ruby’s configure.in and get a ~30% performance boost.
Special thanks… Going out to Jake Douglas for pushing the initial investigation and getting the ball rolling. The whole --enable-pthread thing Ask any Ruby hacker how to easily increase performance in...
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Useful kernel and driver performance tweaks for your Linux server
This article is going to address some kernel and driver tweaks that are interesting and useful. We use several of these in production with excellent performance, but you should proceed with caution...
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Extending ltrace to make your Ruby/Python/Perl/PHP apps faster
If you enjoy this article, subscribe (via RSS or e-mail) and follow me on twitter. A few days ago, Aman (@tmm1) was complaining to me about a slow running process: I want to see what is happening in...
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Rewrite your Ruby VM at runtime to hot patch useful features
If you enjoy this article, subscribe (via RSS or e-mail) and follow me on twitter. Some notes before the blood starts flowin’ CAUTION: What you are about to read is dangerous, non-portable, and (in...
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memprof: A Ruby level memory profiler
If you enjoy this article, subscribe (via RSS or e-mail) and follow me on twitter. What is memprof and why do I care? memprof is a Ruby gem which supplies memory profiler functionality similar to...
View ArticleSlides from Defcon 18: Function hooking for OSX and Linux
Video from Def Con 18 Defcon 18: Function hooking for OSX and Linux from Daniel Hückmann on Vimeo. Slides Function hooking for OSX and Linux
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an obscure kernel feature to get more info about dying processes
If you enjoy this article, subscribe (via RSS or e-mail) and follow me on twitter. tl;dr This post will describe how I stumbled upon a code path in the Linux kernel which allows external programs to...
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How do debuggers keep track of the threads in your program?
If you enjoy this article, subscribe (via RSS or e-mail) and follow me on twitter. tl;dr This post describes the relatively undocumented API for debuggers (or other low level programs) that can be...
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