On Thu, Dec 10, 2020 at 9:16 PM Oscar Salvador <osalvador@xxxxxxx> wrote: > > On Thu, Dec 10, 2020 at 08:14:18PM +0800, Muchun Song wrote: > > Yeah, you are right. But if we do this check can make the code simple. > > > > For example, here is a code snippet. > > > > void func(void) > > { > > if (free_vmemmap_pages_per_hpage()) > > return; > > /* Do something */ > > } > > > > With this patch, the func will be optimized to null when is_power_of_2 > > returns false. > > > > void func(void) > > { > > } > > > > Without this patch, the compiler cannot do this optimization. > > Ok, I misread the changelog. > > So, then is_hugetlb_free_vmemmap_enabled, free_huge_page_vmemmap, > free_vmemmap_pages_per_hpage and hugetlb_vmemmap_init are optimized > out, right? Yes, that's right. I have disassembled to make sure of this. Thanks. > > -- > Oscar Salvador > SUSE L3 -- Yours, Muchun