2 x quad-core system is slower that 2 x dual core on FreeBSD

Alexey Popov lol at chistydom.ru
Thu Nov 22 23:35:37 PST 2007


Kris Kennaway wrote:

>> Now FreeBSD 7-STABLE ULE 8-core server without optimized PHP 
>> realpath_cache_size (producing 2000+ lstats per request) can handle up 
>> to ~24 rps as opposed to  max. 17 rps without your patch. %sys never 
>> grows over %user with your patch. On the server with optimized 
>> realpath_cache_size there's no visible influence of your patch.
> You said "20" before for this configuration, so I'm a bit suspicious 
> about how seriously to treat your measurements :)
Sorry, my mistake. s/ULE/4BSD.

> Anyway, please obtain another lock profiling trace using the same 
> conditions as the previous one (same workload & duration, etc), so we 
> can compare what changed.
OK, I'll make it a little bit later.

Also I tried to find what else is slow in FreeBSD, I tried hwpmc as 
module and in kernel, but it fails with error:
pmc: Unknown Intel CPU.
module_register_init: MOD_LOAD (hwpmc, 0xffffffff804833e0, 
0xffffffff809338a0) error 78

This is related to 
and it is impossible to use hwpmc with modern CPUs.

Is kgmon profiling usable on FreeBSD 7?

With best regards,
Alexey Popov

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