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{ Tag Archives } dtrace

Using VMWare Record/Replay and VProbes for low time-distortion performance profiling

The greatest problem with performance profiling is getting as much information as possible while affecting the results as little as possible.  For my work on pecobro I used mozilla’s JavaScript DTrace probes.  Because the probes are limited to notifications of all function invocations/returns with no discretion and there is no support for JS backtraces, the […]

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master control pecobro, the overkill performance code browser

The title isn’t true yet, but it’s disturbingly almost-true.  Pecobro’s hackish underpinnings have been “accidentally” replaced with surprisingly forward-looking code capable of supporting a much fancier feature set.  (I didn’t mean to, but I got tricked because the incremental cost to doing the ‘right thing’ was always so low.) The trace that you can see […]

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pecobro: the performance code browser (early stage)

At the beginning of last week, I had gotten dtrace working on a Mac Mini using the Mozilla javascript-provider probes.  Very cool stuff, but it left me with several questions about what would really be best to do next: How do I best understand what I’m seeing?  (Most of the codebase is brand new to […]

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Mozilla JavaScript DTrace Probes, visichron style

  This visualization is the result of an adapted visichron.py script (from my chronicle-recorder ‘chroniquery’ bindings) run against the output of a custom DTrace script (using the Mozilla JS providers) on OS X.  It’s a proof-of-possibility rather than anything immediately useful. The differences from the last visichron post (using chronicle-recorder as a back-end) are: Node […]

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