Re: [patch 1/5] mm: add nofail variants of kmalloc kcalloc and kzalloc

Dave Chinner
2010-08-24T13:55:27Z

On Tue, Aug 24, 2010 at 03:29:18PM +0200, Peter Zijlstra wrote:
> On Tue, 2010-08-24 at 03:50 -0700, David Rientjes wrote:
> > These were added as helper functions for documentation and auditability.
> > No future callers should be added.
>
> git grep GFP_NOFAIL isn't auditable enough?
>
> might as well declare these functions depricated if you really want to
> do this.

Also, if you are going to add tight loops, you might want to put a
backoff in the loops like "congestion_wait(BLK_RW_ASYNC, HZ/50);" so
that they don't spin....

FWIW, in all this "allocations can't fail" churn, no one has noticed
that XFS has been doing these "allocations can't fail" loop in
kmem_alloc() and kmem_zone_alloc(), well, forever. I can't ever
remember seeing it report a potential deadlock, though....

Cheers,

Dave.
--
Dave Chinner
david@fromorbit.com