Messages in this thread | | | From | "Izumi, Taku" <> | Subject | RE: [PATCH] mm: Introduce kernelcore=reliable option | Date | Tue, 20 Oct 2015 00:34:51 +0000 |
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Hi Xishi,
> On 2015/10/15 21:32, Taku Izumi 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. > > > > This patch extends 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. > > > > Earlier discussion is at: > > https://lkml.org/lkml/2015/10/9/24 > > > > Hi Taku, > > If user don't want to waste a lot of memory, and he only set > a few memory to mirrored memory, then the kernelcore is very > small, right? That means OS will have a very small normal zone > and a very large movable zone.
Right.
> Kernel allocation could only use the unmovable zone. As the > normal zone is very small, the kernel allocation maybe OOM, > right?
Right.
> Do you mean that we will reuse the movable zone in short-term > solution and create a new zone(mirrored zone) in future?
If there is that kind of requirements, I don't oppose creating a new zone.
Sincerely, Taku Izumi
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