Truss output

UNIX AIX
1

Hello,

I'm using AIX 5.3.12.5 and trying to understand truss output.
I'm running a job with real time of 16 minutes but only 4 minutes of CPU time. I'm trying to understand what the process is doing.

I'm getting a lot of
kread,
kpread,
kwrite,
kpwrite...

localhost:~ x$ grep kread truss.log | wc -l
   90503
localhost:~ x$ grep kwrite truss.log | wc -l
  164596
localhost:~ x$ grep kpwrite truss.log | wc -l
    5817
localhost:~ x$ grep kpread truss.log | wc -l
    5817
localhost:~ x$ wc -l truss.log 
  460125 truss.log
localhost:~ x$ grep select truss.log | wc -l
   65584

What means each one of this calls?

Thanks a lot

2

kread and kwrite look like file or device I/O, the kernel side of read() or write() calls. I'm less sure of kpread and kpwrite, it might be memory paging, but they're not significant.