Re: Linux VM subsystem (Was: Big mallocs, mmap sorrows and double buffering.)

Mark Hemment (markhe@nextd.demon.co.uk)
Thu, 13 Feb 1997 13:26:41 +0000 (GMT)


Hi,

I'm re-implementing the VM subsystem as I write this.

It's still v. much in the prototyping stage, but I've already
got mapping chains working for named pages (without any panics, or
object leaks!!!). When I've got chaining for anon pages working, it
will open the door to some nifty tricks (page flipping for some archs
(such as Intel), true page aging, true swap page clustering, and the death
of swap_out_process()).

My initial changes shrunk the size of the mem_map structure, which caused
an immediate improvement in find_page() (locality of reference and all
that).

Should have a 'developement' patch out in a copy of weeks.

On Wed, 12 Feb 1997, Ingo Molnar wrote:
> On Wed, 12 Feb 1997, A.N.Kuznetsov wrote:
> > The statement is that other unices make this procedure
> > without pain, time grows almost linearly, and when running
> > with low priority in background it practically does not hamper other users.
> > Linux time grows EXPONENTIALLY after starting swap [...]
>
> i remember Linus commenting on such issues about a year ago. He proposed
> some code, and told people to send patches to him.

------------------------------------------------------------------
Mark Hemment, Unix/C Software Engineer (Contractor)
markhe@nextd.demon.co.uk http://www.demon.co.uk/
"Success has many fathers, failure is a B**TARD!" - anon
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