On Wed, Mar 09, 2022 at 08:05:05AM -0800, Randy Dunlap wrote: > Hi Mike, > > On 3/9/22 04:24, Mike Rapoport wrote: > > From: Mike Rapoport <rppt@xxxxxxxxxxxxx> > > > > The existing description of mem= does not cover all the cases and > > differences between how architectures treat it. > > > > Extend the description to match the code. > > > > Signed-off-by: Mike Rapoport <rppt@xxxxxxxxxxxxx> > > --- > > > > This is in a way a followup for the discussion of mem= usage on MIPS: > > > > https://lore.kernel.org/all/1646461289-31992-1-git-send-email-yangtiezhu@xxxxxxxxxxx > > > > .../admin-guide/kernel-parameters.txt | 20 +++++++++++++++++++ > > 1 file changed, 20 insertions(+) > > > > diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt > > index f5a27f067db9..f3597841a031 100644 > > --- a/Documentation/admin-guide/kernel-parameters.txt > > +++ b/Documentation/admin-guide/kernel-parameters.txt > > @@ -2834,6 +2834,15 @@ > > 2 when the kernel is not able to see the whole system memory; > > 3 memory that lies after 'mem=' boundary is excluded from > > the hypervisor, then assigned to KVM guests. > > + 4 to limit the memory available for kdump kernel. > > + > > + [ARC,MICROBLAZE] - the limit applies only to low memory, > > + high memory is not affected. > > + > > + [ARM64] - only limits memory covered by the linear > > + mapping. The NOMAP regions are not affected. > > + > > + [HEXAGON] - must be use to set the memory size, there is > > Above line seems to be missing something? Yes :) > Otherwise looks good AFAIK. > > > > > [X86] Work as limiting max address. Use together > > with memmap= to avoid physical address space collisions. > > @@ -2844,6 +2853,17 @@ > > in above case 3, memory may need be hot added after boot > > if system memory of hypervisor is not sufficient. > > > > + mem=nn[KMG]@ss[KMG] > > + [ARM,MIPS] - override the memory layout reported by > > + firmware. > > + Define a memory region of size nn[KMG] starting at > > + ss[KMG]. > > + Multiple different regions can be specified with > > + multiple mem= parameters on the command line. > > + > > + mem=nn[KMG] [HEXAGON] Set the memory size. > > + Must be specified, otherwise memory size will be 0. > > + > > mem=nopentium [BUGS=X86-32] Disable usage of 4MB pages for kernel > > memory. > > > > -- > ~Randy -- Sincerely yours, Mike.
