Re: VM issue causing high CPU loads

[Yohan]

Trond Myklebust wrote:
> On Thu, 2009-09-03 at 15:39 +0200, Yohan wrote:
>   
> > > As far as I can see, there is no RPCSEC_GSS involved, so credentials
> > > should never expire. They will be reused as long as processes aren't
> > > switching between thousands and thousands of different combinations of
> > > uid, gid and groups.
> > >       
> > My servers are imap servers.
> > Foreach user (~15 million) it have a specific uid over ~10 nfs netapp 
> > storage.
> >     
> OK, so 16 hash buckets are likely to be filled with ~10^6 entries each.
> I can see that might be a performance issue...
>
> So afaics, you did try adjusting the hashtable size. How much larger
> does it have to be before you start to get acceptable performance? If it
> solves your problem we could make hash table sizes adjustable via a
> module parameter, for instance.
>   
I run now with a value of 12, and it's great for me...

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