Re: journaling & VM (was: Re: reiserfs being part of the kernel: it'snot just the code)

Manfred Spraul
2000-06-07T22:22:52Z

"Stephen C. Tweedie" wrote:
>
> Hi,
>
> On Wed, Jun 07, 2000 at 11:40:47PM +0200, Juan J. Quintela wrote:
> > Hi
> > Fair enough, don't put pinned pages in the LRU, *why* do you want put
> > pages in the LRU if you can't freed it when the LRU told it: free that
> > page?
>
> Because even if the information about which page is least recently
> used doesn't help you, the information about which filesystems are
> least active _does_ help.
>

What about using a time based aproach for pinned pages?

* only individually freeable pages are added into the LRU.
* everyone else registers callbacks.
* shrink_mmap estimates (*) the age (in jiffies) of the oldest entry in
the LRU, and then it calls the pressure callbacks with that time.

(*) nr_of_lru_pages/lru_reclaimed_pages_during_last_jiffies. Another
field in "struct page" is too expensive.

--
Manfred