Re: [PATCH 2/3] page allocator: Do not allow interrupts to use ALLOC_HARDER

Mel Gorman
2009-11-09T10:11:28Z

On Wed, Nov 04, 2009 at 10:01:40AM +0100, Pavel Machek wrote:
>
> > I hope we can move this to another thread if people would like to remove
> > this exemption completely instead of talking about this trivial fix, which
> > I doubt there's any objection to.
>
> I'm arguing that this "trivial fix" is wrong, and that you should just
> remove those two lines.
>
> If going into reserves from interrupts hurts, doing that from task
> context will hurt, too. "realtime" task should not be normally allowed
> to "hurt" the system like that.
> Pavel

As David points out, it has been the behaviour of the system for 4 years
and removing it should be made as a separate decision and not in the
guise of a fix. In the particular case causing concern, there are a lot
more allocations from interrupt due to network receive than there are
from the activities of tasks with a high priority.

--
Mel Gorman
Part-time Phd Student Linux Technology Center
University of Limerick IBM Dublin Software Lab