Tune reader_thread poll timeout value

[Frank Ch. Eigler]

f-turgis wrote:

> [...]  The last non tunable or small duration source of wake-up is
> "reader_thread" ppoll timeout value, every 200ms. We compile
> systemtap with a value of 2s or more for our daily use.

Do you notice any adverse effects from this?  For an output-heavy
script for example, does this cause more out-of-buffer conditions?


> So I am proposing to introduce tunables below as an example. Don't
> know if I should have correlated s and ns, also don't know if this
> should also be applied to relay_old.c. Please tell me if this is an
> acceptable change:

Looks OK, though I would rather have just one configurable like
   STP_RELAY_TIMEOUT_MS
from which the .tv_sec and .tv_nsec values are calculated.

(Ideally, a baby PLL could regulate this timeout dynamically, adjusted
with the actual ebb and flow of tracing traffic.)

- FChE