Rik van Riel <riel@conectiva.com.br> writes:
> On 16 Sep 2001, Michael Rothwell wrote:
>
> > Is there a way to tell the VM to prune its cache? Or a way to limit
> > the amount of cache it uses?
>
> Not yet, I'll make a quick hack for this when I get back next
> week. It's pretty obvious now that the 2.4 kernel cannot get
> enough information to select the right pages to evict from
> memory.
Hmm. Perhaps or perhaps it is using the information poorly.
There is an alternative approach to have better aging information.
An address_space can be allocated per mm_struct. And all of the
anonymous pages can be allocated to that address_space. The
address_space can then have an array or better a tree of extents that
list which indexes correspond to which swap pages. With some
pages not being backed.
Getting the allocation of indices correct so that merging will work
is a little trickier then now, as is the case of a private writeable
mapping of a file. But in a lot of other ways the logic becomes
simpler.
> For 2.5 I'm making a VM subsystem with reverse mappings, the
> first iterations are giving very sweet performance so I will
> continue with this project regardless of what other kernel
> hackers might say ;)
Do you have any arguments for the reverse mappings or just for some of
the other side effects that go along with them?
Eric
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
This archive was generated by hypermail 2b29 : Sun Sep 23 2001 - 21:00:19 EST