Re: tracepoint maintainance models

From: Ingo Molnar
Date: Sun Sep 17 2006 - 20:10:36 EST



* Roman Zippel <zippel@xxxxxxxxxxxxxx> wrote:

> And yet again, you offer no prove at all and just work from
> assumptions. You throw in some magic "_full set_" of marker and just
> assume any change in that will completely break static tracers. [...]

i'm not sure i understand what you are trying to say here. Are you
saying that if i replaced half of the static markups with function
attributes (which would still provide equivalent functionality for
dynamic tracers), or if i removed a few dozen static markups with
dynamic scripts (which change too would be transparent to users of
dynamic tracers), that in this case static tracers would /not/ break?
[if yes then that would be the most puzzling suggestion ever posed in
this thread]

> You completely ignore that it might be possible to create some rules
> and educate users that the amount of exported events can't be
> completely static.

no serious trace user would accept it if for example half of their
static tracepoints would go away, because for example they were made
dynamic (or they were made function attributes).

that's the plain meaning of what i said. Were we to accept static
tracers, we'd be stuck with the full set of static tracepoints for a
long time, because users of static tracers would not accept a
significant reduction in the number of tracepoints. (even if those
"reduced" tracepoints were in fact just moved over to dynamic probes)

Was it truly confusing to you what i said? (in words that i thought were
more than clear) Please let me know and i'll try to formulate more
verbosely and more clearly when replying to you. This must be some
fundamental communication issue between you and me.

Ingo
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