On Mon, 2006-12-04 at 11:44 -0500, Adam Jackson wrote:
On Mon, 2006-12-04 at 02:13 -0500, Paul Michael Reilly wrote:
> When running top, I see that X is consuming 40% of memory which is not
> surprising since I am running two X sessions with 3200x1200 (dual
> head, radeon, open source) along with long running firefox,
> thunderbird and VNC (also 3200x1200) apps). But when I bring up the
> Soundcard Detection tool under KDE top shows Xorg is consistently
> grabbing 93% of the CPU even when all I am doing is typing this
> message. That would certainly explain a lot of the lag in response to
> mouse clicks from the app. :-) Switching to Gnome and running top
> there shows varying, but high (60%ish) CPU use with the Soundcard
> Detection tool still running in both sessions. But with Gnome,
> response to mousee clicks is fine, even with the high X CPU use.
So you've found that some use profile makes X use all the CPU. Now you
need to find out _what_ in X is taking all the time. You need to either
use a tool like oprofile or sysprof to extract that information,
one easy way that might give a good clue is cstop (for context-switch
top); it's a system tap script that reports the top context switchers
http://www.fenrus.org/cstop.stp
run this as
stap -v cstop.stp
(you need the kernel-debuginfo rpm installed for this to work)
X will probably be way high up there, but so will the culprit which
makes X do a lot of work, at least that's my experience....