New KTR trace for mouse freezing/stuttering in 7.0-RC1

John Baldwin jhb at
Wed Jan 30 06:23:01 PST 2008

On Friday 25 January 2008 05:31:34 pm Joe Peterson wrote:
> John Baldwin wrote:
> > Hmm, when I look at that graph using schedgraphy from HEAD it just looks
> > like xtrs is using up all the CPU.
> Yeah, xtrs is eating a lot of CPU, but I've never seen this affect the
> mouse movement (making it really jerky) the same way on, e.g., Linux.
> And the xtrs test is just a way to *reliably* make it happen.  It
> happens intermittently all of the time (at least every few minutes, and
> often in small batches) even when the system is pretty idle...
> 					-Joe

So it's a scheduling bug where a compute bound process is starving an
interactive one basically.  :)  Since you are using ULE, I would try
talking to Jeff (jeff@) to see if he can address this.

John Baldwin

More information about the freebsd-stable mailing list