On Mon, Nov 5, 2018 at 4:32 PM Bart Van Assche <bvanassche@xxxxxxx> wrote: > > On Mon, 2018-11-05 at 16:11 -0800, Alexander Duyck wrote: > > If we really don't care then why even bother with the switch statement > > anyway? It seems like you could just do one ternary operator and be > > done with it. Basically all you need is: > > return (defined(CONFIG_ZONE_DMA) && (flags & __GFP_DMA)) ? KMALLOC_DMA : > > (flags & __GFP_RECLAIMABLE) ? KMALLOC_RECLAIM : 0; > > > > Why bother with all the extra complexity of the switch statement? > > I don't think that defined() can be used in a C expression. Hence the > IS_ENABLED() macro. If you fix that, leave out four superfluous parentheses, > test your patch, post that patch and cc me then I will add my Reviewed-by. > > Bart. Actually the defined macro is used multiple spots in if statements throughout the kernel. The reason for IS_ENABLED is to address the fact that we can be dealing with macros that indicate if they are built in or a module since those end up being two different defines depending on if you select 'y' or 'm'. Thanks. - Alex
