On Fri, Apr 12, 2024 at 10:01:29AM +0200, Vlastimil Babka wrote: > On 4/11/24 6:51 PM, Christoph Lameter (Ampere) wrote: > > On Thu, 11 Apr 2024, Haifeng Xu wrote: > > > >> @@ -1875,6 +1875,13 @@ static inline struct slab *alloc_slab_page(gfp_t flags, int node, > >> struct slab *slab; > >> unsigned int order = oo_order(oo); > >> > >> + /* > >> + * If fallback to the minimum order allocation and the order is 0, > >> + * clear the __GFP_COMP flag. > >> + */ > >> + if (order == 0) > >> + flags = flags & ~__GFP_COMP; > > > > > > This would be better placed in allocate_slab() when the need for a > > fallback to a lower order is detected after the first call to alloc_slab_page(). > > Yeah. Although I don't really see the harm of __GFP_COMP with order-0 in the > first place, if the only issue is that the error output might be confusing. > I'd also hope we should eventually get rid of those odd non-__GFP_COMP > high-order allocations and then can remove the flag. The patch seems pointless to me. I wouldn't clear the flag. If somebody finds it confusing, that's really just their expectations being wrong. folio_alloc() sets __GFP_COMP on all allocations, whether or not they're order 0.
