Re: Performance regressions in 2.6.30-rc7?

[Andrew Morton <akpm@linux-foundation.org>]

On Thu, 28 May 2009 22:49:28 +0200 Diego Calleja <diegocg@gmail.com> wrote:

> Hi, phoronix.com has run some benchmarks in 2.6.30-rc7 [1], there're some
> good numbers, but there's also a couple of regressions. Some people think
> that phoronix benchmarks are not very serious/reliable/meaningful, but i
> thought it'd be better to post false warnings than letting real regressions
> slip in without notice.
> 
> The regressions would be:
> - 7zip MIPS ("7zr b" command) http://www.phoronix.com/data/img/results/linux_2630/1.png
> 
> - tiobench latency (not throughput) using 64MB writes with 32 threads
> http://www.phoronix.com/data/img/results/linux_2630/7.png
> 
> -gnupg 2GB file encryption http://www.phoronix.com/data/img/results/linux_2630/3.png
> 
> 
> Full article: http://www.phoronix.com/scan.php?page=article&item=linux_2630

Those regressions are huge.  They appear to be on compute-intensive
workloads too.

I wonder if some expensive debugging option turned itself on or
something silly like that.