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authorMike Rapoport <rppt@linux.ibm.com>2022-03-10 09:27:36 +0100
committerJonathan Corbet <corbet@lwn.net>2022-03-16 22:57:56 +0100
commit75c05fabb873367d9e64f063dda8a310c4c58826 (patch)
tree6e785027fa139c3717292c090cef6dc87445e381 /Documentation/admin-guide/kernel-parameters.txt
parentdocs/zh_CN: Add sched-nice-design Chinese translation (diff)
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docs/kernel-parameters: update description of mem=
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@linux.ibm.com> Link: https://lore.kernel.org/r/20220310082736.1346366-1-rppt@kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Diffstat (limited to '')
-rw-r--r--Documentation/admin-guide/kernel-parameters.txt18
1 files changed, 18 insertions, 0 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index f5a27f067db9..5b84cca62990 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -2827,6 +2827,9 @@
For details see: Documentation/admin-guide/hw-vuln/mds.rst
+ mem=nn[KMG] [HEXAGON] Set the memory size.
+ Must be specified, otherwise memory size will be 0.
+
mem=nn[KMG] [KNL,BOOT] Force usage of a specific amount of memory
Amount of memory to be used in cases as follows:
@@ -2834,6 +2837,13 @@
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.
[X86] Work as limiting max address. Use together
with memmap= to avoid physical address space collisions.
@@ -2844,6 +2854,14 @@
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=nopentium [BUGS=X86-32] Disable usage of 4MB pages for kernel
memory.