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Re: Tune reader_thread poll timeout value
- From: fche at redhat dot com (Frank Ch. Eigler)
- To: "Turgis, Frederic" <f-turgis at ti dot com>
- Cc: "systemtap at sourceware dot org" <systemtap at sourceware dot org>
- Date: Tue, 01 May 2012 17:30:19 -0400
- Subject: Re: Tune reader_thread poll timeout value
- References: <28BE1A38672C8B4481BB423D0FD1F22E18F55BE1@DNCE04.ent.ti.com>
> [...] 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
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.)