Re: [RFC/PATCH v2] mm: Introduce GFP_PANIC for non-failing allocations

[Pekka Enberg <penberg@cs.helsinki.fi>]

Hi Rik,

On Fri, 2009-05-08 at 10:37 -0400, Rik van Riel wrote:
> > @@ -1556,7 +1556,8 @@ nofail_alloc:
> >  				zonelist, high_zoneidx, ALLOC_NO_WATERMARKS);
> >  			if (page)
> >  				goto got_pg;
> > -			if (gfp_mask & __GFP_NOFAIL) {
> > +			/* GFP_PANIC sets both flags */
> > +			if ((gfp_mask & __GFP_NOFAIL) && !(gfp_mask & __GFP_NORETRY)) {
> >  				congestion_wait(WRITE, HZ/50);
> 
> Do you mean ((gfp_mask & GFP_PANIC) == GFP_PANIC))  ?

No, we only want to loop if __GFP_NOFAIL is set but __GFP_NORETRY is not
set.

> 
> > @@ -1670,6 +1671,9 @@ nopage:
> >  		dump_stack();
> >  		show_mem();
> >  	}
> > +	if (unlikely(gfp_mask & GFP_PANIC))
> > +		panic("Out of memory: %s order: %d, gfp_mask:0x%x\n",
> > +			p->comm, order, gfp_mask);
> 
> Ditto here.

Yes, indeed. Fixed up. Thanks!