Re: [RFC 0/3] Recursive reclaim (on __PF_MEMALLOC)

Nick Piggin
2007-09-11T07:41:36Z

On Mon, Sep 10, 2007 at 12:29:32PM -0700, Christoph Lameter wrote:
> On Wed, 5 Sep 2007, Nick Piggin wrote:
>
> > Implementation issues aside, the problem is there and I would like to
> > see it fixed regardless if some/most/or all users in practice don't
> > hit it.
>
> I am all for fixing the problem but the solution can be much simpler and
> more universal. F.e. the amount of tcp data in flight may be controlled
> via some limit so that other subsystems can continue to function even if
> we are overwhelmed by network traffic. Peter's approach establishes the
> limit by failing PF_MEMALLOC allocations. If that occurs then other

Can you to propose a solution that is much simpler and more universal?

> subsystems (like the disk, or even fork/exec or memory management
> allocation) will no longer operate since their allocations no longer
> succeed which will make the system even more fragile and may lead to
> subsequent failures.

You're saying we shouldn't fix an out of memory deadlocks because
that might result in ENOMEM errors being returned, rather than the
system locking up?