On 2019/7/23 16:33, Mike Rapoport wrote: > On Tue, Jul 23, 2019 at 01:51:13PM +0800, Hanjun Guo wrote: >> From: Jia He <hejianet@xxxxxxxxx> >> >> After skipping some invalid pfns in memmap_init_zone(), there is still >> some room for improvement. >> >> E.g. if pfn and pfn+1 are in the same memblock region, we can simply pfn++ >> instead of doing the binary search in memblock_next_valid_pfn. >> >> Furthermore, if the pfn is in a gap of two memory region, skip to next >> region directly to speedup the binary search. > How much speed up do you see with this improvements relatively to simple > binary search in memblock_next_valid_pfn()? The major speedup on my platform is the previous patch in this patch set, not this one, I think it's related to sparse memory mode for different platforms. Thanks Hanjun >