Lines Matching +full:memory +full:- +full:to +full:- +full:memory

2 crashkernel memory reservation on arm64
7 Kdump mechanism is used to capture a corrupted kernel vmcore so that
8 it can be subsequently analyzed. In order to do this, a preliminarily
9 reserved memory is needed to pre-load the kdump kernel and boot such
12 That reserved memory for kdump is adapted to be able to minimally
19 Through the kernel parameters below, memory can be reserved accordingly
21 large chunk of memomy can be found. The low memory reservation needs to
22 be considered if the crashkernel is reserved from the high memory area.
24 - crashkernel=size@offset
25 - crashkernel=size
26 - crashkernel=size,high crashkernel=size,low
28 Low memory and high memory
31 For kdump reservations, low memory is the memory area under a specific
32 limit, usually decided by the accessible address bits of the DMA-capable
33 devices needed by the kdump kernel to run. Those devices not related to
34 vmcore dumping can be ignored. On arm64, the low memory upper bound is
37 whole system RAM is low memory. Outside of the low memory described
38 above, the rest of system RAM is considered high memory.
44 --------------------------
46 The crashkernel memory must be reserved at the user-specified region or
51 -------------------
53 The crashkernel memory region will be reserved in any available position
54 according to the search order:
56 Firstly, the kernel searches the low memory area for an available region
59 If searching for low memory fails, the kernel falls back to searching
60 the high memory area for an available region of the specified size. If
61 the reservation in high memory succeeds, a default size reservation in
62 the low memory will be done. Currently the default size is 128M,
63 sufficient for the low memory needs of the kdump kernel.
66 reservations. The user would not need to know the system memory layout
70 ---------------------------------------------
72 crashkernel=size,(high|low) are an important supplement to
73 crashkernel=size. They allows the user to specify how much memory needs
74 to be allocated from the high memory and low memory respectively. On
75 many systems the low memory is precious and crashkernel reservations
76 from this area should be kept to a minimum.
78 To reserve memory for crashkernel=size,high, searching is first
79 attempted from the high memory region. If the reservation succeeds, the
80 low memory reservation will be done subsequently.
82 If reservation from the high memory failed, the kernel falls back to
83 searching the low memory with the specified size in crashkernel=,high.
84 If it succeeds, no further reservation for low memory is needed.
88 - If crashkernel=,low is not specified, the default low memory
91 - if crashkernel=0,low is specified, it means that the low memory