Re: Gtk performance issues from a user's point of view

[Soeren Sandmann <sandmann daimi au dk>]

Federico Mena Quintero <federico ximian com> writes:

> - The X server uses 30% of the time.  5.5% is fbSolidFillmmx().  7.9% is
> "in kernel" - no idea what that means.  Some DMA or something?

"In kernel" just means the kernel is running. It could be a system
call or a page fault or an interrupt handler. For system calls and
page faults the blame gets assigned to the application that caused
them. For interrupt the blame gets assigned to whatever application
happened to be running. So basically, in this case it means that 7.9%
of the time spent in the X server is system calls or page faults.

I do have a longterm plan to have sysprof report (1) _what_ the kernel
was doing and (2) what parts of userspace apps were responsible for
making it do those things.

In sysprof HEAD "In kernel" does actually get assigned to the
stacktrace that caused it to happen, but it still doesn't tell you
what the "In kernel" code was doing.

Sysprof HEAD is a little rough at the moment though.

> > - Is there any way to get to know how many times a specific function was
> > called and/or how long it took to proceed?
> 
> Not with sysprof, unfortunately.  You'd need something like gprof for
> that.

A valgrind skin to do the call counting would probably be a better
bet. Writing valgrind skins is actually not that hard.


Soren