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Re: precompiled probing scenarios
Frank Ch. Eigler wrote:
Hi -
On Fri, Oct 20, 2006 at 02:26:32PM -0500, David Smith wrote:
[...]
Pass 4: compiled C into "stap_d833fd040735ddde57a23bebb4456542_201.ko"
Is that "_201" at the end the getuid()? I wonder if maybe that could
be hashed into the content instead.
Nope, that is part of the hash. It might be the number of input bits,
I'm unsure.
I don't hash the getuid(), since:
- by default your cache is stored in your home directory
- who you are doesn't change the pass 2-4 output
Copying /tmp/stapYrsXWC/stap_d833fd040735ddde57a23bebb4456542_201.ko to
/home/dsmith/.stap_cache/d/8/stap_d833fd040735ddde57a23bebb4456542_201.ko
Copying /tmp/stapYrsXWC/stap_d833fd040735ddde57a23bebb4456542_201.c to
/home/dsmith/.stap_cache/d/8/stap_d833fd040735ddde57a23bebb4456542_201.c
These messages should probably show up only under -vv (verbosity 2)
or higher.
Easy enough to fix. Currently they only show up under '-v'.
[...]
# stap -v -e 'probe begin { log("hi") }' [...]
Pass 2: analyzed script: 1 probe(s), 1 function(s), 0 global(s) in
10usr/0sys/11real ms.
Using cached result
"/home/dsmith/.stap_cache/d/8/stap_d833fd040735ddde57a23bebb4456542_201.ko"
as "/tmp/stapJFisJO/stap_d833fd040735ddde57a23bebb4456542_201.ko"
This "Using cached result" part could be rephrased as a pair:
Pass 3: skipped translation
Pass 4: reused cached module stap_deadbeef
[...] A module (currently) gets pulled from the cache after pass 2,
even if '-p3' or '-p4' was specified on the command line.
The translator would still need to spit out (regenerate) the C source
code for a -p3 run.
Nope. I actually cache the module and the C file so I can skip pass 3
but still preserve semantics.
Hmm. How about something like:
Pass 3: Using cached
/home/dsmith/.stap_cache/d/8/stap_d833fd040735ddde57a23bebb4456542_201.c
Pass 4: Using cached
/home/dsmith/.stap_cache/d/8/stap_d833fd040735ddde57a23bebb4456542_201.ko
--
David Smith
dsmith@redhat.com
Red Hat
http://www.redhat.com
256.217.0141 (direct)
256.837.0057 (fax)