Re: [PATCH] block,blkcg: use __GFP_NOWARN for best-effort allocations in blkcg

[Vlastimil Babka]

On 11/29/2016 05:38 PM, Tejun Heo wrote:
> On Tue, Nov 29, 2016 at 08:25:07AM +0100, Michal Hocko wrote:
> > --- a/include/linux/gfp.h
> > +++ b/include/linux/gfp.h
> > @@ -246,7 +246,7 @@ struct vm_area_struct;
> >  #define GFP_ATOMIC	(__GFP_HIGH|__GFP_ATOMIC|__GFP_KSWAPD_RECLAIM)
> >  #define GFP_KERNEL	(__GFP_RECLAIM | __GFP_IO | __GFP_FS)
> >  #define GFP_KERNEL_ACCOUNT (GFP_KERNEL | __GFP_ACCOUNT)
> > -#define GFP_NOWAIT	(__GFP_KSWAPD_RECLAIM)
> > +#define GFP_NOWAIT	(__GFP_KSWAPD_RECLAIM|__GFP_NOWARN)
> >  #define GFP_NOIO	(__GFP_RECLAIM)
> >  #define GFP_NOFS	(__GFP_RECLAIM | __GFP_IO)
> >  #define GFP_TEMPORARY	(__GFP_RECLAIM | __GFP_IO | __GFP_FS | \
> >
> > this will not catch users who are doing gfp & ~__GFP_DIRECT_RECLAIM but
> > I would rather not make warn_alloc() even more cluttered with checks.
>
> Yeah, FWIW, looks good to me.

Me too. Just don't forget to update the comment describing GFP_NOWAIT and check 
the existing users if duplicite __GFP_NOWARN can be removed, and if they really 
want to be doing GFP_NOWAIT and not GFP_ATOMIC.

Also dunno what about Tejun's eariler patch.