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Re: LMbench as gcc performance regression test?

Daniel Jacobowitz wrote:
On Sun, Aug 31, 2003 at 12:21:37AM -0700, Dan Kegel wrote: has an interesting little graph
of LMBench results vs. Linux kernel version, all done with the
same compiler.

Has anyone seen a similar graph showing LMBench results vs. gcc version,
all done with the same Linux kernel?
And does everyone agree that's a meaningful way to compare the
performance of code generated by different compilers?

It's been a while since I looked at lmbench but: why do you think this would be useful? It's a system and kernel benchmark; I doubt optimization makes much difference at all.

I need to make sure that moving to a newer compiler for our kernel will cause no performance regressions. Before bothering to bring up a real-world networking application and measuring its performance under the new compiler, it seems sensible to use a couple microbenchmarks to verify that identifiable parts of the system have not degraded in performance.

I myself am quite convinced I need to move to a newer compiler,
since I keep running into problems building various things with
old compilers, but my users are very conservative and skeptical;
I have to build a solid case for updating.  Hence the insane amount
of time I spent figuring out and documenting how to build and test
the various versions of gcc and glibc (,
and then understanding the regression test failures.
- Dan

Dan Kegel

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