Hi Serge, On Wed, Nov 22, 2023 at 09:24:03PM +0300, Serge Semin wrote: > Besides of the already described reasons the pages backended memory holes > might be persistent due to having memory mapped IO spaces behind those > ranges in the framework of flatmem kernel config. Add such note to the > init_unavailable_range() method kdoc in order to point out to one more > reason of having the function executed for such regions. > > Signed-off-by: Serge Semin <fancer.lancer@xxxxxxxxx> > > --- > > Please let me know if the IO-space pages must be initialized somehow > differently rather relying on free_area_init() executing the > init_unavailable_range() method. Maybe I'm missing something, but why do you need struct pages in the IO space? > --- > mm/mm_init.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/mm/mm_init.c b/mm/mm_init.c > index 077bfe393b5e..3fa33e2d32ba 100644 > --- a/mm/mm_init.c > +++ b/mm/mm_init.c > @@ -796,6 +796,7 @@ overlap_memmap_init(unsigned long zone, unsigned long *pfn) > * - physical memory bank size is not necessarily the exact multiple of the > * arbitrary section size > * - early reserved memory may not be listed in memblock.memory > + * - memory mapped IO space > * - memory layouts defined with memmap= kernel parameter may not align > * nicely with memmap sections > * > -- > 2.42.1 > -- Sincerely yours, Mike.
