Firefox/Projects/Startup Time Improvements/joelr notes: Difference between revisions

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(Created page with '= Intro = I'm trying to figure out where Firefox startup time goes, up to the return from BrowserStartup (Javascript function). I'm also manipulating DTrace into telling me whe…')
 
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=== August 24, 2009 ===
=== August 24, 2009 ===


Should really be using ''vtimestamp'' instead of ''timestamp'' since the latter includes DTrace overhead. ''vtimestamp'' counts CPU time of the current thread and should not be used in the BEGIN and END sections of the D script.
''vtimestamp'' measures CPU time of the current thread, excluding IO and DTrace overhead. ''timestamp'' can still be used for deltas but the goal is to use as few pid$target probes as possible as they affect ''timestamp'' when dtrace has to switch between kernel and userland. io and syscall providers are fast and run in the kernel.


My DTrace scripts live [http://github.com/wagerlabs/firefox-startup/tree/master here].
My DTrace scripts live [http://github.com/wagerlabs/firefox-startup/tree/master here].

Revision as of 18:49, 24 August 2009

Intro

I'm trying to figure out where Firefox startup time goes, up to the return from BrowserStartup (Javascript function). I'm also manipulating DTrace into telling me where time is going, without making any assumptions.

Current status

August 21, 2009

Blogged.

August 24, 2009

vtimestamp measures CPU time of the current thread, excluding IO and DTrace overhead. timestamp can still be used for deltas but the goal is to use as few pid$target probes as possible as they affect timestamp when dtrace has to switch between kernel and userland. io and syscall providers are fast and run in the kernel.

My DTrace scripts live here.

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