Disabling skipping probes based on delays

Frank Ch. Eigler fche@redhat.com
Wed Aug 27 22:02:00 GMT 2008


Darren Hart <dvhltc@us.ibm.com> writes:

> I was hoping to use stap to simulate a scenario where only 25% of the
> CPU is available to the system.  The best way we came up with to do this
> was to introduce a delay in the scheduler_tick.  I have succeeded in
> adding a udelay() into the scheduler_tick via guru mode and embedded C.

Interesting approach.

> Unfortunately, stap bails out with the following message:
> WARNING: Number of errors: 0, skipped probes: 103

These could be due to locking timeouts, if your probes handlers
manipulate globals.  You could try again with -DMAXSKIPPED=99999.

- FChE



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