On 4/26/21 9:15 AM, Mike Rapoport wrote: > On Mon, Apr 26, 2021 at 11:55:00AM +0000, Vladimir Isaev wrote: >> Hi Mike, >> >> On Mon, April 26, 2021 2:29 PM, Mike Rapoport wrote: >>> On Mon, Apr 26, 2021 at 01:10:04PM +0300, Vladimir Isaev wrote: >>>> - max_zone_pfn[ZONE_HIGHMEM] = min_low_pfn; >>>> + max_zone_pfn[ZONE_HIGHMEM] = max_high_pfn; >>> This is correct with PAE40, but it will break !PAE40 when "highmem" has lower >>> addresses than lowmem. >>> >>> It rather should be something like: >>> >>> if (IS_ENABLED(CONFIG_ARC_HAS_PAE40)) >>> max_zone_pfn[ZONE_HIGHMEM] = max_high_pfn; >>> else >>> max_zone_pfn[ZONE_HIGHMEM] = min_low_pfn; >>> >> Not sure if I understand why we should have min_low_pfn here. In !PAE40 >> case max_high_pfn just will be smaller than min_low_pfn. > Hmm, actually, you are right. This should be fine. But still worth adding a comment. If this could trip the person who did the massive cross-arch rework then I don't know what mere mortals would run into ;-) -Vineet