acpi, memory-hotplug: support getting hotplug info from SRAT

[karo-tx-linux.git] / Documentation / kernel-parameters.txt

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 4c5b3f993bbbf2eb60095b18537285e1ac7ffb14..766087781ecd6a7ae52b2843cb58c22fc678a8fb 100644 (file)
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -594,6 +594,9 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
                        is selected automatically. Check
                        Documentation/kdump/kdump.txt for further details.
 
+       crashkernel_low=size[KMG]
+                       [KNL, x86] parts under 4G.
+
        crashkernel=range1:size1[,range2:size2,...][@offset]
                        [KNL] Same as above, but depends on the memory
                        in the running system. The syntax of range is
@@ -1637,6 +1640,42 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
                        that the amount of memory usable for all allocations
                        is not too small.
 
+       movablemem_map=acpi
+                       [KNL,X86,IA-64,PPC] This parameter is similar to
+                       memmap except it specifies the memory map of
+                       ZONE_MOVABLE.
+                       This option inform the kernel to use Hot Pluggable bit
+                       in flags from SRAT from ACPI BIOS to determine which
+                       memory devices could be hotplugged. The corresponding
+                       memory ranges will be set as ZONE_MOVABLE.
+                       NOTE: Whatever node the kernel resides in will always
+                             be un-hotpluggable.
+
+       movablemem_map=nn[KMG]@ss[KMG]
+                       [KNL,X86,IA-64,PPC] This parameter is similar to
+                       memmap except it specifies the memory map of
+                       ZONE_MOVABLE.
+                       If user specifies memory ranges, the info in SRAT will
+                       be ingored. And it works like the following:
+                       - If more ranges are all within one node, then from
+                         lowest ss to the end of the node will be ZONE_MOVABLE.
+                       - If a range is within a node, then from ss to the end
+                         of the node will be ZONE_MOVABLE.
+                       - If a range covers two or more nodes, then from ss to
+                         the end of the 1st node will be ZONE_MOVABLE, and all
+                         the rest nodes will only have ZONE_MOVABLE.
+                       If memmap is specified at the same time, the
+                       movablemem_map will be limited within the memmap
+                       areas. If kernelcore or movablecore is also specified,
+                       movablemem_map will have higher priority to be
+                       satisfied. So the administrator should be careful that
+                       the amount of movablemem_map areas are not too large.
+                       Otherwise kernel won't have enough memory to start.
+                       NOTE: We don't stop users specifying the node the
+                             kernel resides in as hotpluggable so that this
+                             option can be used as a workaround of firmware
+                              bugs.
+
        MTD_Partition=  [MTD]
                        Format: <name>,<region-number>,<size>,<offset>