On Sun, Jan 21, 2024 at 10:45:55PM -0800, Christoph Hellwig wrote: > > + int length = BBTOB(bp->b_length); > > + int order; > > + > > + order = ilog2(length); > > + if ((1 << order) < length) > > + order = ilog2(length - 1) + 1; > > + > > + if (order <= PAGE_SHIFT) > > + order = 0; > > + else > > + order -= PAGE_SHIFT; > > Shouldn't this simply use get_order()? Huh. Yes, it should. I went looking for a helper and didn't find one in the mm or folio code. Now you point it out, I find that it is in it's own asm header (include/asm-generic/getorder.h) so it's no wonder I didn't find it. Why is it in include/asm-generic? There's nothing asm related to that function or it's implementation.... -Dave. -- Dave Chinner david@xxxxxxxxxxxxx