On 09/03/2010 20:14, David Xu wrote: > jan.gr...@bristol.ac.uk wrote: >> On Thu, 2 Sep 2010, Andriy Gapon wrote: >> >> >>> on 02/09/2010 12:08 jan.gr...@bristol.ac.uk said the following: >>> >>>> On Wed, 1 Sep 2010, Ivan Voras wrote: >>>> >>>> >>>>> On 09/01/10 15:08, jan.gr...@bristol.ac.uk wrote: >>>>> >>>>>> I'm running -STABLE with a kde-derived desktop. This setup >>>>>> (which is pretty standard) is providing abysmal interactive >>>>>> performance on an eight-core machine whenever I try to do >>>>>> anything CPU-intensive (such as building a port). >>>>>> >>>>>> Basically, trying to build anything from ports rapidly >>>>>> renders everything else so "non-interactive" in the eyes of >>>>>> the scheduler that, for instance, switching between virtual >>>>>> desktops (I have six of them in reasonably frequent use) >>>>>> takes about a minute of painful waiting on redraws to >>>>>> complete. >>>>>> >>>>> Are you sure this is about the scheduler or maybe bad X11 >>>>> drivers? >>>>> >>>> Not 100%, but mostly convinced; I've just started looking at >>>> this. It's my first stab at what might be going on. X11 >>>> performance is usually pretty snappy. There's no paging >>>> pressure at all. >>>> >>> From my experience: 1. system with Athlon II X2 250 CPU and >>> onboard AMD graphics - no issues with interaction between >>> buildworld and GUI with all KDE4 effects enabled (OpenGL). 2. >>> system with comparable Core2 Duo CPU and onboard Intel graphics >>> (G33) - enabling OpenGL desktop effects in KDE4 leads to the >>> consequences like what you describe. With all GUI bells and >>> whistles disabled the system behaves quite like the AMD system. >>> >> >> All desktop effects are disabled. The graphics are from an nVidia >> GeForce 8500 GT (G86) with the X.org driver. (It's not _just_ >> desktop behaviour that's affected, though: the box runs a number of >> small headless [interactive] server processes which also appear to >> get rapidly starved of CPU time.) >> >> The behaviour isn't visible with the 4bsd scheduler; "stuff" >> generally remains snappy and responsive. >> >> I'll keep poking around and see if I can get to the bottom of it. >> >> >> >> > I think sysctl kern.sched.preempt_thresh is too low, default is only > 64. I always tune it up to 200 on my desktop machine which is > running gnome and other GUI applications, for a heavy GUI deskkop, I > would tune it up to 224 to get better result. >
For reference how did you arrive at 224 for a result ? -- jhell,v _______________________________________________ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"