NFS server bottlenecks
Ivan Voras
ivoras at freebsd.org
Sat Oct 20 19:29:08 UTC 2012
On 20 October 2012 14:45, Rick Macklem <rmacklem at uoguelph.ca> wrote:
> Ivan Voras wrote:
>> I don't know how to interpret the rise in context switches; as this is
>> kernel code, I'd expect no context switches. I hope someone else can
>> explain.
>>
> Don't the mtx_lock() calls spin for a little while and then context
> switch if another thread still has it locked?
Yes, but are in-kernel context switches also counted? I was assuming
they are light-weight enough not to count.
> Hmm, I didn't look, but were there any tests using UDP mounts?
> (I would have thought that your patch would mainly affect UDP mounts,
> since that is when my version still has the single LRU queue/mutex.
Another assumption - I thought UDP was the default.
> As I think you know, my concern with your patch would be correctness
> for UDP, not performance.)
Yes.
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