Friday, April 16, 2010

Kernel and user profiling with dtrace

Just put together a short dtrace script for profiling both userland and kernel activity.

#!/usr/sbin/dtrace -s
#pragma D option quiet



  printf("%5s %20s %20s %10s\n","PID","EXECNAME","FUNC","COUNT");
  printa("%5d %20s %20A %10@d\n",@);
  printa("%5d %20s %#20a %10@d\n",@k);

The script samples the current pc for both user land and kernel about 100x per second. There's some risk of over counting since there's one probe for user and one probe for kernel. Every second the code prints out the top 25 user and kernel routines, broken down by pid and executable name. The output looks like:

  PID             EXECNAME                 FUNC                 COUNT
  556                 Xorg`pixman_image_unref  1
  556                 Xorg`pixman_fill         1
  556                 Xorg`memcpy                     1
    0                sched unix`dispatch_softint                1
    0                sched unix`dispatch_hardint                2
    0                sched unix`mach_cpu_idle                   91

Saturday, April 10, 2010

New Redpoint albums

I was thrilled to see that there are two new full releases from Redpoint, "Nostalgia for Now" and "Sense of Summer". They have also set up a youtube site with a bunch of videos.