Resending since the last attempt bounced.
On Wed, Oct 16, 2013 at 03:21:31PM +0530, Siddhesh Poyarekar wrote:
On Tue, Oct 15, 2013 at 10:27:36PM +0200, Reindl Harald wrote:
> >> Do you really run "gnome-open --help" 1000 times per reasonable
unit of
> >> time (or ever)? Please stop using bogus comparisons and highly
> >> contrived tests. They do nothing to help your argument.
> >
> > This isn't totally invalid. I assume that some shell scripts with tight
loops are the only thing that actually
> > benefits from prelinking today. People write those, unfortunately.
>
> it is - they are *not* loading a lot of dynmaic linked libraries
It is spawning a program a bunch of times, which results in program
load time becoming all the more relevant. Shell scripts that spawn
multiple programs in tight loops are not exactly uncommon, so please
don't pretend that they don't exist.
> [harry@srv-rhsoft:~]$ ldd /usr/bin/bash
> linux-vdso.so.1 => (0x00007fffc9764000)
> libtinfo.so.5 => /lib64/libtinfo.so.5 (0x00007f99b21aa000)
> libdl.so.2 => /lib64/libdl.so.2 (0x00007f99b1fa6000)
> libc.so.6 => /lib64/libc.so.6 (0x00007f99b1be4000)
> /lib64/ld-linux-x86-64.so.2 (0x00007f99b23ee000)
>
> > I'm attaching a deliberately badly written script which should be fairly
representative, alas. I can' benchmark it
> > right now because the system isn't idle, but if someone else wants to have
a go at it, be my guest.
>
> if you *only* can measure it if your system is *idle* than you have what we called
> "maske dby noise" already in this thread and that is *not* significant
You haven't understood the point of the statement - a benchmark
measurement is reliable only if the 'before' and 'after' measurements
are done in identical conditions. In that context, an idle system is
the ideal pre-condition. That point has nothing to do with whether
the performance improvement is evident when the system is under any
amount of load.
Siddhesh