Hi,
During the development of "unSPEC" [1] benchmarking suite, I made some
interesting observations regarding prelink.
- Here are some measurements (for LibreOffice [2] loading time in
seconds) done using the "unSPEC" bench-marking suite. These numbers
are repeatable and you are encouraged to try "unSPEC" to do
independent validation of these numbers.
- hkario (modern SSD based system, cache flushed): (1.816, 1.811,
1.797, 1.827 with prelink), (2.034, 2.042, 2.027, 2.016 without
prelink)
- hkario (modern SSD based system, cache intact): (2.155, 2.121,
2.101, 2.299 with prelink), (2.311, 2.052, 2.047, 2.037 without
prelink)
- halfie (T430s): (10.725, 10.095, 10.378, 10.568 with prelink),
(8.901, 8.993, 9.075, 9.448, 9.489 without prelink)
- danpb (T530): I see basically no measurable difference in times with
or without prelink - quite a lot of variation, but all in same
ballpark, (8.374, 7.849, 8.457, 7.673, 7.608, 8.031, 8.350, 8.183,
7.381 with prelink), (7.366, 8.009, 7.500, 7.949, 8.208, 8.351,
7.849, without prelink).
- For building kernels (using the "kernel-bench" [3] component of unSPEC
suite), prelink saved <= 250 ms over the non-prelink environment
(which took 1m19.138s). hkario even reports worse performance numbers
for the prelink environment. Additionally, we have specialized
softwares like ccache and distcc to solve long-compilation-time
problems.
In short, we could not distinguish the performance gains of prelink over
the "background noise" in many (or even most) cases.
So, I was wondering if you are aware of any use-cases where prelink
provides measurable benefits. It would be awesome if you could run
unSPEC on your systems and report back the numbers.
unSPEC is easy to use and doesn't take much time (or steps) to run. For
more information, please see the following links.
References:
[1]
https://github.com/kholia/unSPEC
[2]
https://github.com/kholia/unSPEC/tree/master/LibreOffice
[3]
https://github.com/kholia/unSPEC/tree/master/kernel-bench
--
Dhiru
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All very well and nice, but what does this have to do with the Security
List ?
Also, most people will switch off pre-linking on servers, due to
erroneous reports of lib and binary changes, that are caused by pre-linking.
Regards,
Tristan
--
Tristan Santore BSc MBCS
TS4523-RIPE
Network and Infrastructure Operations
InterNexusConnect
Mobile +44-78-55069812
Tristan.Santore(a)internexusconnect.net
Former Thawte Notary
(Please note: Thawte has closed its WoT programme down,
and I am therefore no longer able to accredit trust)
For Fedora related issues, please email me at:
TSantore(a)fedoraproject.org