Re: [PATCH 02/10] mm: system wide ALLOC_NO_WATERMARK

Christoph Lameter
2007-08-06T23:14:59Z

On Mon, 6 Aug 2007, Daniel Phillips wrote:

> Correct. That is what the throttling part of these patches is about.

Where are those patches?

> In order to fix the vm writeout deadlock problem properly, two things
> are necessary:
>
> 1) Throttle the vm writeout path to use a bounded amount of memory
>
> 2) Provide access to a sufficiently large amount of reserve memory for
> each memory user in the vm writeout path
>
> You can understand every detail of this patch set and the following ones
> coming from Peter in terms of those two requirements.

AFAICT: This patchset is not throttling processes but failing allocations.
The patchset does not reconfigure the memory reserves as expected. Instead
new reserve logic is added. And I suspect that we have the same issues as
in earlier releases with various corner cases not being covered. Code is
added that is supposedly not used. If it ever is on a large config then we
are in very deep trouble by the new code paths themselves that serialize
things in order to give some allocations precendence over the other
allocations that are made to fail ....