On Wed, Jan 13, 2021 at 09:56:49AM +0100, Oscar Salvador wrote: > On Mon, Jan 11, 2021 at 09:40:16PM +0200, Mike Rapoport wrote: > > From: Mike Rapoport <rppt@xxxxxxxxxxxxx> > > > > The first 4Kb of memory is a BIOS owned area and to avoid its allocation > > for the kernel it was not listed in e820 tables as memory. As the result, > > pfn 0 was never recognised by the generic memory management and it is not a > > part of neither node 0 nor ZONE_DMA. > > So, since it never was added to memblock.memory structs, it was not > initialized by init_unavailable_mem, right? Actually it was initialized by init_unavailable_mem() and got zone=0 and node=0, but the DMA zone started from pfn 1, so pfn 0 was never a part of ZONE_DMA. > -- > Oscar Salvador > SUSE L3 -- Sincerely yours, Mike.
