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

Christoph Lameter
2007-09-10T19:29:42Z

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
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.