[webkit-dev] parallel rendering in WebKit

[Zoltan Herczeg]

Hi,

as all of you probably know, smp based systems are getting widespread even
in the embedded domain, and we hope we can speed up webkit on these
systems. We did some profiling, and seemed the platform dependent
rendering took 50% of the total runtime (at least on our test platforms).
We are thinking about adding some parallel rendering support for WebKit,
probably mostly platform dependent code, but the threading support could
be reused by different ports.

The plan is opening a rendering thread for each document object. This
thread is dedicated to rendering, the resource management is still done by
the main thread. In other words, functions like drawRect (in
GraphicsContext.h) creates a small object, which contains the arguments of
the called function, and passing this object to the thread. The thread
would do the painting, and send back the object after it is processed. The
main thread can free the memory space of the object later, and dereference
the resources (we hope resources like fonts and images are not need to be
duplicated).

This is still a vague idea, and we are still investigating the
possibilities. What is your opinion? Do you know about any major blockers
we should know about?

Thanks in advance,
Zoltan