John Baldwin wrote:
On Thursday 24 January 2008 06:22:57 am Sam Leffler wrote:
Joe Peterson wrote:
In an attempt to track down this mouse freezing/stuttering (i.e. "jerky
mouse movement) behavior in FreeBSD 7.0-RC1, I have come up with a
reliable way to cause it to happen, and I have created a longer trace
showing the results. Note that I am using the ULE scheduler.
In general, it becomes easier to see the effect if there is CPU
activity. I have noticed it during kernel compiles, while at the same
time loading web pages in firefox that contain images (and moving the
mouse while this is happening). But a more controlled way to see it is
to run something that uses some CPU and then generating lots of X events.
In my case, I start "xtrs" (TRS-80 emulator) in Model IV mode, which
happens to poll for input, using the CPU. Then I move the mouse back
and forth quickly between windows in "focus under mouse" mode (in my
case, a KDE focus mode), which causes many focus events quickly. In
about 15 or 20 seconds, the mouse reliably starts to show erratic
movement, not moving smoothly.
I really hope this can shed more light on what might be going on. Here
is the trace:
http://www.skyrush.com/downloads/ktr_ule_4.out
This is an interesting trace. It appears that something is blocking
threads in the runq from running for 2 seconds! I don't see what it is
from the trace data. It sort of looks like the last thing that ran is
the swi4 which is likely a callout (need to check the log file contents
to be certain). If the callback function does something it wouldn't
necessarily be visible in the schedgraph plot. If you could stick a
dmesg from booting out in the same spot it might be worthwhile. Also if
you rebuild the kernel the kernel with DIAGNOSTIC then softclock() will
complain about callouts that take longer than 2ms to run. This might
generate too much noise in which case you can adjust the threshold by
editing the code in sys/kern/kern_timeout.c.
Hmm, when I look at that graph using schedgraphy from HEAD it just looks
like xtrs is using up all the CPU. I didn't see the 2 second window where
nothing was running.
Sigh, you are correct. I backrev'd the machine where I ran schedgraph
to RELENG_7 and didn't notice the old version mis-parses the ktr file.
The graph is totally different w/ schedgraph from HEAD.
Sorry Joe for misleading you.
Sam
_______________________________________________
freebsd-stable@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-stable
To unsubscribe, send any mail to "[EMAIL PROTECTED]"
