TODO list, v0.01

TODO list, v0.01

[Rik van Riel]

Hi,

here's the MM TODO list, very first version, just listing
the projects people are working on.

Other projects are yet to be added -- what ones?

Rik.
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----------------------------------------------

Linux Memory Management TODO & being-done list.



Erik W. Biedermann <ebiederm+erik@npwt.de>

	Large file (40 bits on 32 bit) support in the page cache
	Write back caching through the page cache.
	Ability to use swap for non-process things. Shared memory etc.

Benjamin C.R. LaHaise <blah@kvack.org>

	Reverse PTE lookup (together with Stephen Tweedie).
	Swapout overhaul (comes with PTE chaining).

Stephen C. Tweedie

	Reverse PTE lookup (together with Benjamin C.R. LaHaise).
	Swapin readahead.
	MM subsystem overhaul.

Rik van Riel <H.H.vanRiel@phys.uu.nl>

	Zone based memory allocator.
	Better swapout clustering.	(help welcome)
	Real swapping (program suspension).
	Out of memory handler.		(help welcome)

Werner Fink <werner@suse.de>

	???

Re: TODO list, v0.01

[Stephen C. Tweedie]

Hi,

On Thu, 11 Jun 1998 23:59:45 +0200 (MET DST), Rik van Riel
<H.H.vanRiel@phys.uu.nl> said:

> Hi,
> here's the MM TODO list, very first version, just listing
> the projects people are working on.

> Other projects are yet to be added -- what ones?

Lots --- mainly sorting out performance and fragmentation issues for
2.2 in the short term.  More after Usenix...

--Stephen

Re: TODO list, v0.01

[Rik van Riel]

On Fri, 12 Jun 1998, Stephen C. Tweedie wrote:
> On Thu, 11 Jun 1998 23:59:45 +0200 (MET DST), Rik van Riel
> <H.H.vanRiel@phys.uu.nl> said:
> 
> > Other projects are yet to be added -- what ones?
> 
> Lots --- mainly sorting out performance and fragmentation issues for
> 2.2 in the short term.  More after Usenix...

The fragmentation issue will get better when I have written
the new allocator. When I keep it simple and really trivial
I might even convince Linus to merge it in a stable release.

The performance will mainly need swapin readahead. I've
found swapout to be quite fast already.
The other performance issue is with multiple scanning of
shared pages, which will be fixed for free once the PTE
chaining of you and Ben is done...

Rik.
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Re: TODO list, v0.01

[Dr. Werner Fink]

On Thu, Jun 11, 1998 at 11:59:45PM +0200, Rik van Riel wrote:
> 
> here's the MM TODO list, very first version, just listing
> the projects people are working on.
> 
> Other projects are yet to be added -- what ones?
> 
> Rik.

[...]

> 
> Werner Fink <werner@suse.de>
> 
> 	???
> 

??? == We should get a better recover time/behaviour of the mm for small
       systems under high load.  Currently small systems with 2.1.10X
       (RAM < 32MB, sometimes < 64MB) do loose in comparision to 2.0.33/34.


          Werner

Re: TODO list, v0.01

[Stephen Tweedie]

Hi,

In article <19980615185647.50925@boole.suse.de>, "Dr. Werner Fink"
<werner@suse.de> writes:

> On Thu, Jun 11, 1998 at 11:59:45PM +0200, Rik van Riel wrote:
>> 
>> here's the MM TODO list, very first version, just listing
>> the projects people are working on.

> ??? == We should get a better recover time/behaviour of the mm for small
>        systems under high load.  Currently small systems with 2.1.10X
>        (RAM < 32MB, sometimes < 64MB) do loose in comparision to 2.0.33/34.

It's the number one problem we need to fix for 2.2.  Fortunately a lot
of people are aware of the problem and we spent a lot of time talking
about it at expo and Usenix.  I think we've got a good handle on how
to start tackling the obvious problems, but there will still be a lot of
tuning required before we can release a 2.2 kernel and call it stable.

I'll write up an outline of what I think we need to start doing once
I'm back from Usenix.

--Stephen

Re: TODO list, v0.01

[Rik van Riel]

On Tue, 16 Jun 1998, Stephen Tweedie wrote:
> In article <19980615185647.50925@boole.suse.de>, "Dr. Werner Fink"
> <werner@suse.de> writes:
> 
> > ??? == We should get a better recover time/behaviour of the mm for small
> >        systems under high load.  Currently small systems with 2.1.10X
> >        (RAM < 32MB, sometimes < 64MB) do loose in comparision to 2.0.33/34.
> 
> It's the number one problem we need to fix for 2.2.  Fortunately a lot
> of people are aware of the problem and we spent a lot of time talking
> about it at expo and Usenix.  I think we've got a good handle on how
> to start tackling the obvious problems, but there will still be a lot of
> tuning required before we can release a 2.2 kernel and call it stable.

We should probably start with Werner's patch for linux-2.1.102
(if it hasn't been integrated yet).

> I'll write up an outline of what I think we need to start doing once
> I'm back from Usenix.

I have the outlines for a nice and simple zone allocator.
We can push this in for 2.3, it's probably too late for
2.2 :(
However, if we can prove that it works correctly, we might
be able to sneak it in behind Linus' back :-)

Rik.
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| Linux memory management tour guide.        H.H.vanRiel@phys.uu.nl |
| Scouting Vries cubscout leader.      http://www.phys.uu.nl/~riel/ |
+-------------------------------------------------------------------+

Re: TODO list, v0.01

[Rik van Riel]

On Sat, 13 Jun 1998 ralf@uni-koblenz.de wrote:
> On Thu, Jun 11, 1998 at 11:59:45PM +0200, Rik van Riel wrote:
> 
> > Benjamin C.R. LaHaise <blah@kvack.org>
> > 	Reverse PTE lookup (together with Stephen Tweedie).
> > 
> > Stephen C. Tweedie
> > 	Reverse PTE lookup (together with Benjamin C.R. LaHaise).
> 
> The reverse pte lookup, is this stuff for 2.2?  In the meantime I came to
> the conclusion that the only sane way to fix the virtual cache problems
> on MIPS, so from my point of view this is a must for 2.2.

I don't think Linus will let it in before 2.2 :(

Therefor, our only option would be to work closely
together and push one huge new VM subsystem at Linus
when he's least suspected :)

And if we can't convince him to put it in 2.2, we
should just push for a really short-cycle 2.3...

Oh, if we _do_ want to do this, we'll have to
cooperate more closely and keep each other up to
date on what we're busy with.
As soon as I've installed Stampede Linux and the
devel kernel again, I'll be updating my MM page
at least once a week again...

Rik.
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| Linux memory management tour guide.        H.H.vanRiel@phys.uu.nl |
| Scouting Vries cubscout leader.      http://www.phys.uu.nl/~riel/ |
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