Re: [RFC][PATCH 1/6] mm: Introduce __GFP_NO_OOM_KILL

[Rafael J. Wysocki]

On Monday 11 May 2009, David Rientjes wrote:
> On Sun, 10 May 2009, Rafael J. Wysocki wrote:
> 
> > Index: linux-2.6/mm/page_alloc.c
> > ===================================================================
> > --- linux-2.6.orig/mm/page_alloc.c
> > +++ linux-2.6/mm/page_alloc.c
> > @@ -1619,8 +1619,12 @@ nofail_alloc:
> >  			goto got_pg;
> >  		}
> >  
> > -		/* The OOM killer will not help higher order allocs so fail */
> > -		if (order > PAGE_ALLOC_COSTLY_ORDER) {
> > +		/*
> > +		 * The OOM killer will not help higher order allocs so fail.
> > +		 * Also fail if the caller doesn't want the OOM killer to run.
> > +		 */
> > +		if (order > PAGE_ALLOC_COSTLY_ORDER
> > +				|| (gfp_mask & __GFP_NO_OOM_KILL)) {
> >  			clear_zonelist_oom(zonelist, gfp_mask);
> >  			goto nopage;
> >  		}
> > Index: linux-2.6/include/linux/gfp.h
> > ===================================================================
> > --- linux-2.6.orig/include/linux/gfp.h
> > +++ linux-2.6/include/linux/gfp.h
> > @@ -51,8 +51,9 @@ struct vm_area_struct;
> >  #define __GFP_THISNODE	((__force gfp_t)0x40000u)/* No fallback, no policies */
> >  #define __GFP_RECLAIMABLE ((__force gfp_t)0x80000u) /* Page is reclaimable */
> >  #define __GFP_MOVABLE	((__force gfp_t)0x100000u)  /* Page is movable */
> > +#define __GFP_NO_OOM_KILL ((__force gfp_t)0x200000u)  /* Don't invoke out_of_memory() */
> >  
> > -#define __GFP_BITS_SHIFT 21	/* Room for 21 __GFP_FOO bits */
> > +#define __GFP_BITS_SHIFT 22	/* Number of __GFP_FOO bits */
> >  #define __GFP_BITS_MASK ((__force gfp_t)((1 << __GFP_BITS_SHIFT) - 1))
> >  
> >  /* This equals 0, but use constants in case they ever change */
> > 
> 
> Nack, unnecessary in mmotm and my patch series from 
> http://lkml.org/lkml/2009/5/10/118.

Andrew, what's your opinion, please?

I can wait with these patches until the dust settles in the mm land.

David, which patch in your series causes this to be unnecessary?

Best,
Rafael
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