Re: Reclaiming vnodes

[Adam Hamsik <haaaad%gmail.com@localhost>]

Hi,
On Sep,Tuesday 15 2009, at 1:43 AM, Wolfgang Solfrank wrote:

> hi,
>
> > Vnodes are only allocated and there is no vnode recycling. If  
> > number of used vnodes in a system is > than kern.vnodes_num_hiwat 
> > (in percents of maxvnodes) vrele thread will be woken up and it  
> > will start with releasing of free vnodes until number of used  
> > vnodes is < than kern.vnodes_num_lowat.
>
> And how will that help the situation?
>
> As far as I understand the situation the system is in a state that  
> it can't
> handle the amount of resource requests forwarded to it, and thus  
> will probably
> need to sleep on the request for some new vnode anyway.  Maybe you  
> are shifting
> the problem a bit further along, but it doesn't help in principle  
> anyway.

Yes it helps because vnodes are not released in zfs context but in a  
different one where is only VOP_RECLAIM called without any other zfs  
locks held. We shift vnode reclaiming from fs context to vrele thread.

Regards

Adam.