Re: Terminate process that fails on a constrained allocation

[Andi Kleen <ak@suse.de>]

On Wednesday 08 February 2006 23:11, Christoph Lameter wrote:
> On Wed, 8 Feb 2006, Andrew Morton wrote:
> 
> > > I think it should be put into 2.6.16. Andrew?
> > 
> > Does every single caller of __alloc_pages(__GFP_FS) correctly handle a NULL
> > return?  I doubt it, in which case this patch will cause oopses and hangs.
> 
> I sent you a patch with static inline.....

noinline 

> But I am having second thoughts  
> about this patch. Paul is partially right. Maybe we can move the logic 
> into the out_of_memory handler for now? That would allow us to implement 
> more sophisticated things later 

I have my doubts that's really worth it, but ok.

> (for example page migration would allow us 
> to move memory of processes that can also allocate on other nodes from the 
> nodes where we lack memory) and Paul may put something in there to 
> address his concerns.
> 
> ---
> 
> Terminate process that fails on a constrained allocation

Patch looks good for me too.  Thanks.

Unfortunately Andrew's point with the GFP_NOFS still applies :/
But I would consider any caller of this not handling NULL be broken.
Andrew do you have any stronger evidence it's a real problem?

Another way would be to force a default non strict policy with GFP_NOFS, but
that would be somewhat ugly again and impact the fast paths.

-Andi