40% slowdown with dynamic /bin/sh

M. Warner Losh imp at bsdimp.com
Tue Nov 25 21:43:41 PST 2003

In message: <20031126052626.GI15294 at wombat.localnet>
            Michael Edenfield <kutulu at kutulu.org> writes:
: * M. Warner Losh <imp at bsdimp.com> [031125 12:07]:
: > In message: <00a701c3b33c$f798c5e0$b9844051 at insultant.net>
: >             "boyd, rounin" <boyd at insultant.net> writes:
: > : i see that there some doubt about whether running lots of
: > : shell scripts ever happens.  what happens when you
: > : use make?  lots of shells get run and they run small
: > : (one line?) scripts.
: > 
: > make buildworld slows down < 1% when you switch from static /bin/sh to
: > dynamic.
: I'm all for dynamic / and dynamic /bin/sh, but this doesn't even come
: close to what I observed on my systems.  I see anywhere from 15% to 20%
: slowdown in buildworld, depending on how bad my hardware already is.  I
: posted my most recent numbers earlier.

My dual athlon make -j 4 buildworld differed by about 16-20 seconds on
a 36 minute buildworld.

: It's difficult to get lots of these numbers, unfortunately, because it
: takes a good 6-8 hours just to complete one build.  But the numbers are
: fairly consistant across the different degrees of old crappy hardware I
: have.

So you are seeing a about an hour slowdown (16% slowdown on 6 hours is
1 hour) from before/after?  Or are you seeing an hour slowdown from
4.x -> 5.2-beta?

Also, so we can characterize where the suckage happens, how much
RAM/CPU does your system have?


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