On 12/01/17 at 10:42am, Michal Hocko wrote: > On Fri 01-12-17 17:29:51, Dave Young wrote: > > On 12/01/17 at 10:19am, Michal Hocko wrote: > > > On Fri 01-12-17 16:56:57, Dave Young wrote: > > > > On 11/30/17 at 10:35am, Michal Hocko wrote: > > > [...] > > > > > Can we exclude that range from the memblock allocator instead? E.g. what > > > > > happens if somebody allocates from that range? > > > > > > > > It is a EFI BGRT image buffer provided by firmware, they are reserved > > > > always and can not be used to allocate memory. > > > > > > Hmm, I see but I was actually suggesting to remove this range from the > > > memblock allocator altogether (memblock_remove) as it shouldn't be there > > > in the first place. > > > > Oh, I'm not sure because it is introduced as a way for efi to reserve > > boot services areas to be persistent across kexec reboot. See > > drivers/firmware/efi/efi.c: efi_mem_reserve(), BGRT is only one user > > of it, there is esrt and maybe other users, I do not know if it is safe > > :( > > Hmm, so it this range ever backed by a valid pfn? I think it is in normal boot, just it does not appear in e820 across kdump reboot. For kdump kexec_tools provided e820 the last pfn only covers the kdump crashkernel ranges thus it is not mapped. > -- > Michal Hocko > SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
