Re: BFS vs. mainline scheduler benchmarks and measurements

[Jens Axboe]

On Thu, Sep 10 2009, Ingo Molnar wrote:
> 
> * Jens Axboe <jens.axboe@xxxxxxxxxx> wrote:
> 
> > On Thu, Sep 10 2009, Peter Zijlstra wrote:
> > > On Wed, 2009-09-09 at 14:20 +0200, Jens Axboe wrote:
> > > > 
> > > > One thing I also noticed is that when I have logged in, I run xmodmap
> > > > manually to load some keymappings (I always tell myself to add this to
> > > > the log in scripts, but I suspend/resume this laptop for weeks at the
> > > > time and forget before the next boot). With the stock kernel, xmodmap
> > > > will halt X updates and take forever to run. With BFS, it returned
> > > > instantly. As I would expect.
> > > 
> > > Can you provide a little more detail (I'm a xmodmap n00b), how 
> > > does one run xmodmap and maybe provide your xmodmap config?
> > 
> > Will do, let me get the notebook and strace time it on both bfs 
> > and mainline.
> 
> A 'perf stat' comparison would be nice as well - that will show us 
> events strace doesnt show, and shows us the basic scheduler behavior 
> as well.
> 
> A 'full' trace could be done as well via trace-cmd.c (attached), if 
> you enable:
> 
>   CONFIG_CONTEXT_SWITCH_TRACER=y
> 
> and did something like:
> 
>   trace-cmd -s xmodmap ... > trace.txt

trace.txt attached. Steven, you seem to go through a lot of trouble to
find the debugfs path, yet at the very end do:

> 	system("cat /debug/tracing/trace");

which doesn't seem quite right :-)

-- 
Jens Axboe

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