compiled printf support increases C source and ko module sizes a bit

Mark Wielaard mjw@redhat.com
Fri Nov 25 13:57:00 GMT 2011


Hi,

I just said the same on irc (#systemtap on irc.freenode.net), but
realized it is a holiday in the USA, so people might not be online atm.

I noticed the compiled printf support does bloat the generated src.c
file a bit for things like:
stap -e 'probe process("/bin/ls").function("*")
        { printf("%s(%s)\n", probefunc(), $$parms) }'

It produces with stap 1.6 a 781K .c source file and a 1.2M .ko file.
  and with stap git trunk a 1.1M .c source file and a 1.5M .ko file.

Estimated against stap 1.6 vs stap git trunk since using
-DSTP_LEGACY_PRINT doesn't really strip the code out, just ifdefs it
way. But it does look like most of the extra size comes from the
compiled printf support.

Maybe not so alarming, but certainly a noticeable increase. Are the
benefits of compiled printf big enough to warrant such a size increase?

Cheers,

Mark



More information about the Systemtap mailing list