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

Rohit Seth
2006-08-17T17:14:28Z

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