On Sat, 28 Nov 2015 00:03:55 +0900 Taku Izumi <izumi.taku@xxxxxxxxxxxxxx> wrote: > Xeon E7 v3 based systems supports Address Range Mirroring > and UEFI BIOS complied with UEFI spec 2.5 can notify which > ranges are reliable (mirrored) via EFI memory map. > Now Linux kernel utilize its information and allocates > boot time memory from reliable region. > > My requirement is: > - allocate kernel memory from reliable region > - allocate user memory from non-reliable region > > In order to meet my requirement, ZONE_MOVABLE is useful. > By arranging non-reliable range into ZONE_MOVABLE, > reliable memory is only used for kernel allocations. > > My idea is to extend existing "kernelcore" option and > introduces kernelcore=reliable option. By specifying > "reliable" instead of specifying the amount of memory, > non-reliable region will be arranged into ZONE_MOVABLE. It is unfortunate that the kernel presently refers to this memory as "mirrored", but this patchset introduces the new term "reliable". I think it would be better if we use "mirrored" throughout. Of course, mirroring isn't the only way to get reliable memory. Perhaps if a part of the system memory has ECC correction then this also can be accessed using "reliable", in which case your proposed naming makes sense. reliable == mirrored || ecc? Secondly, does this patchset mean that kernelcore=reliable and kernelcore=100M are exclusive? Or can the user specify "kernelcore=reliable,kernelcore=100M" to use 100M of reliable memory for kernelcore? This is unclear from the documentation and I suggest that this be spelled out. -- 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>