On Sun, Mar 27, 2022 at 3:41 AM Paolo Bonzini <pbonzini@xxxxxxxxxx> wrote: > > On 3/26/22 01:31, Vipin Sharma wrote: > >>> -static void slot_rmap_walk_next(struct slot_rmap_walk_iterator *iterator) > >>> +static noinline void > >> > >> What is the reason to add noinline? > > > > My understanding is that since this method is called from > > __always_inline methods, noinline will avoid gcc inlining the > > slot_rmap_walk_next in those functions and generate smaller code. > > > > Iterators are written in such a way that it's way more beneficial to > inline them. After inlining, compilers replace the aggregates (in this > case, struct slot_rmap_walk_iterator) with one variable per field and > that in turn enables a lot of optimizations, so the iterators should > actually be always_inline if anything. > > For the same reason I'd guess the effect on the generated code should be > small (next time please include the output of "size mmu.o"), but should > still be there. I'll do a quick check of the generated code and apply > the patch. > > Paolo > Let me know if you are still planning to modify the current patch by removing "noinline" and merge or if you prefer a v2 without noinline. Thanks Vipin
