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Subject: Re: this 48-core box...
From: Adrian Chadd <adrian@freebsd.org>
To: Vincent Schut <schut@sarvision.nl>
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.. just as a data point - there was a thread a while ago about numeric
processing performance on linux vs bsd.

It all boiled down to how jemalloc versus the linux allocator(s) allocate
blocks. jemalloc will page align things after a certain size. Linux didn't.
So when doing numeric processing, there was a lot of cache aliasing going
on leading to inefficient cache usage and redundant memory operations.

When the same workload on Linux was run on FreeBSD but with the Linux
library/allocators, the performance was identical.

No-one followed through. I think I may have to write a blog post about it.


-adrian