[Devel] Re: [RFC][PATCH 5/7] UBC: kernel memory accounting (core)

[Rohit Seth]

On Thu, 2006-08-17 at 17:35 +0400, Kirill Korotaev wrote:

> > My preference would be to have container (I keep on saying container,
> > but resource beancounter) pointer embeded in task, mm(not sure),
> > address_space and anon_vma structures.  This should allow us to track
> > user land pages optimally.  But for tracking kernel usage on behalf of
> > user, we will have to use an additional field (unless we can re-use
> > mapping).  Please correct me if I'm wrong, though all the kernel
> > resources will be allocated/freed in context of a user process.  And at
> > that time we know if a allocation should succeed or not.  So we may
> > actually not need to track kernel pages that closely.  We are not going
> > to run reclaim on any of them anyways.  
> objects are really allocated in process context
> (except for TCP/IP and other softirqs which are done in arbitrary
> process context!)

Can these pages be tagged using mapping field of the page struct.

> And objects are not always freed in correct context (!).
> 
You mean beyond Networking and softirq.

> Note, page_ub is not for _user_ pages. user pages accounting will be added
> in next patch set. page_ub is added to track kernel allocations.
> 

But will the page_ub be used for some purpose for user land pages?

-rohit