NUMA support; tweaking TCP for GPRS

[John Baldwin]

On Thursday 12 November 2009 9:08:35 pm Sean Hamilton wrote:
> Greetings -hackers,
> 
> I have two unrelated questions.
> 
> First, what is the status of NUMA support in FreeBSD? Is
> there a performance penalty on Nehalem-class systems,
> compared with Linux, which advertises NUMA awareness? Google
> seems to turn up very little on this subject.

Yes, there is a penalty.  I have some very simplistic NUMA support in a p4 
branch (//depot/user/jhb/numa/...) that just makes threads allocate memory 
close to the current CPU when requesting a free page.  It's not very general 
purpose, but it can be useful if you pin all your tasks to specific packages.  
I haven't tested it with non-pinned workloads to see what effect it has.

-- 
John Baldwin