On Wed 20-03-19 17:06:24, Baoquan He wrote: > On 03/20/19 at 09:46am, Michal Hocko wrote: > > On Wed 20-03-19 16:07:32, Baoquan He wrote: > > > In function node_states_check_changes_online(), N_HIGH_MEMORY is used > > > to substitute ZONE_HIGHMEM directly. This is not right. N_HIGH_MEMORY > > > always has value '3' if CONFIG_HIGHMEM=y, while ZONE_HIGHMEM's value > > > is not. It depends on whether CONFIG_ZONE_DMA/CONFIG_ZONE_DMA32 are > > > enabled. Obviously it's not true for CONFIG_ZONE_DMA32 on 32bit system, > > > and CONFIG_ZONE_DMA is also optional. > > > > > > Replace it with ZONE_HIGHMEM. > > > > N*MEMORY is confusing as hell but I am really curious whether we have > > ZONE_DMA32 and ZONE_HIGMEM together? > > Not sure. AFAIK, on x86_32 it can't be. > > > > > That being said N.*MEMORY is intended to check for nodes rather than > > zones so the patch looks good to me but I think the above explanation is > > misleading and will add even more mud to the picture when somebody tries > > to understand what the heck is going on here. > > Yes, agree. I also thought this again after I sent out patch, feel log is not > good. As you said, they are value of enum node_states and enum zone_type > separately. > > How about this: > > ~~~ > In function node_states_check_changes_online(), N_HIGH_MEMORY is used > to substitute ZONE_HIGHMEM directly. This is not right. N_HIGH_MEMORY > is to mark the memory state of node. Here zone index is checked, which > should be compared with 'ZONE_HIGHMEM' accordingly. > > Replace it with ZONE_HIGHMEM.
OK, this is better. Thanks! Feel free to stamp the patch with Acked-by: Michal Hocko <mho...@suse.com> -- Michal Hocko SUSE Labs
