lkml.org 
[lkml]   [2009]   [Dec]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: x264 benchmarks BFS vs CFS
From
Date
On Thu, 2009-12-17 at 12:00 +0100, Kasper Sandberg wrote:
> On Thu, 2009-12-17 at 11:53 +0100, Ingo Molnar wrote:
> > * Jason Garrett-Glaser <darkshikari@gmail.com> wrote:
> >
> > > On Thu, Dec 17, 2009 at 1:33 AM, Kasper Sandberg <lkml@metanurb.dk> wrote:
> > > > well well :) nothing quite speaks out like graphs..
> > > >
> > > > http://doom10.org/index.php?topic=78.0
> > > >
> > > >
> > > >
> > > > regards,
> > > > Kasper Sandberg
> > >
> > > Yeah, I sent this to Mike a bit ago. Seems that .32 has basically tied
> > > it--and given the strict thread-ordering expectations of x264, you basically
> > > can't expect it to do any better, though I'm curious what's responsible for
> > > the gap in "veryslow", even with SCHED_BATCH enabled.
> > >
> > > The most odd case is that of "ultrafast", in which CFS immediately ties BFS
> > > when we enable SCHED_BATCH. We're doing some further testing to see exactly
>
> Thats kinda besides the point.
>
> all these tunables and weirdness is _NEVER_ going to work for people.

Fact is, it is working for a great number of people, the vast majority
of whom don't even know where the knobs are, much less what they do.

> now forgive me for being so blunt, but for a user, having to do
> echo x264 > /proc/cfs/gief_me_performance_on_app
> or
> echo some_benchmark > x264 > /proc/cfs/gief_me_performance_on_app

Theatrics noted.

> just isnt usable, bfs matches, even exceeds cfs on all accounts, with
> ZERO user tuning, so while cfs may be able to nearly match up with a ton
> of application specific stuff, that just doesnt work for a normal user.

Seems you haven't done much benchmarking. BFS has strengths as well as
weaknesses, all schedulers do.

> not to mention that bfs does this whilst not loosing interactivity,
> something which cfs certainly cannot boast.

Not true. I sent Con hard evidence of a severe problem area wrt
interactivity, and hard numbers showing other places where BFS needs
some work. But hey, if BFS blows your skirt up, use it and be happy.

-Mike



\
 
 \ /
  Last update: 2009-12-17 14:33    [from the cache]
©2003-2011 Jasper Spaans