Messages in this thread | | | From | David Laight <> | Subject | RE: [PATCH 1/4] mm/page_alloc: fix non cma alloc context | Date | Fri, 17 Jul 2020 08:32:07 +0000 |
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From: js1304@gmail.com > Sent: 15 July 2020 06:05 > From: Joonsoo Kim <iamjoonsoo.kim@lge.com> > > Currently, preventing cma area in page allocation is implemented by using > current_gfp_context(). However, there are two problems of this > implementation. ... > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index 6416d08..cd53894 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c ... > @@ -3693,6 +3691,16 @@ alloc_flags_nofragment(struct zone *zone, gfp_t gfp_mask) > return alloc_flags; > } > > +static inline void current_alloc_flags(gfp_t gfp_mask, > + unsigned int *alloc_flags) > +{ > + unsigned int pflags = READ_ONCE(current->flags); > + > + if (!(pflags & PF_MEMALLOC_NOCMA) && > + gfp_migratetype(gfp_mask) == MIGRATE_MOVABLE) > + *alloc_flags |= ALLOC_CMA; > +} > +
I'd guess this would be easier to understand and probably generate better code if renamed and used as: alloc_flags |= can_alloc_cma(gpf_mask);
Given it is a 'static inline' the compiler might end up generating the same code. If you needed to clear a flag doing: alloc_flags = current_alloc_flags(gpf_mask, alloc_flags); is much better for non-inlined function.
David
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