Re: [PATCH] mm/page_alloc: fix memalloc_nocma_{save/restore} APIs

[Matthew Wilcox]

On Tue, Jul 21, 2020 at 02:38:56PM +0200, Vlastimil Babka wrote:
> On 7/21/20 2:05 PM, Matthew Wilcox wrote:
> > On Tue, Jul 21, 2020 at 12:28:49PM +0900, js1304@xxxxxxxxx wrote:
> >> @@ -4619,8 +4631,10 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
> >>  		wake_all_kswapds(order, gfp_mask, ac);
> >>  
> >>  	reserve_flags = __gfp_pfmemalloc_flags(gfp_mask);
> >> -	if (reserve_flags)
> >> +	if (reserve_flags) {
> >>  		alloc_flags = reserve_flags;
> >> +		alloc_flags = current_alloc_flags(gfp_mask, alloc_flags);
> >> +	}
> > 
> > Is this right?  Shouldn't you be passing reserve_flags to
> > current_alloc_flags() here?  Also, there's no need to add { } here.
> 
> Note the "alloc_flags = reserve_flags;" line is not being deleted here. But if
> it was, your points would be true, and yeah it would be a bit more tidy.

Oh ... I should wake up a little more.

Yeah, I'd recommend just doing this:

-		alloc_flags = reserve_flags;
+		alloc_flags = current_alloc_flags(gfp_mask, reserve_flags);