diff options
| author | Yinghai Lu <yinghai@kernel.org> | 2013-04-15 22:23:47 -0700 |
|---|---|---|
| committer | H. Peter Anvin <hpa@linux.intel.com> | 2013-04-17 12:35:33 -0700 |
| commit | 55a20ee7804ab64ac90bcdd4e2868a42829e2784 (patch) | |
| tree | ae8701054b3da8ac5d46d1cbdbb9c67a5ebd0591 /Documentation/kernel-parameters.txt | |
| parent | c729de8fcea37a1c444e81857eace12494c804a9 (diff) | |
x86, kdump: Retore crashkernel= to allocate under 896M
Vivek found old kexec-tools does not work new kernel anymore.
So change back crashkernel= back to old behavoir, and add crashkernel_high=
to let user decide if buffer could be above 4G, and also new kexec-tools will
be needed.
-v2: let crashkernel=X override crashkernel_high=
update description about _high will be ignored by crashkernel=X
-v3: update description about kernel-parameters.txt according to Vivek.
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/1366089828-19692-4-git-send-email-yinghai@kernel.org
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Diffstat (limited to 'Documentation/kernel-parameters.txt')
| -rw-r--r-- | Documentation/kernel-parameters.txt | 13 |
1 files changed, 11 insertions, 2 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index cff672da248..709eb3edc6b 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -603,9 +603,16 @@ bytes respectively. Such letter suffixes can also be entirely omitted. a memory unit (amount[KMG]). See also Documentation/kdump/kdump.txt for an example. + crashkernel_high=size[KMG] + [KNL, x86_64] range could be above 4G. Allow kernel + to allocate physical memory region from top, so could + be above 4G if system have more than 4G ram installed. + Otherwise memory region will be allocated below 4G, if + available. + It will be ignored if crashkernel=X is specified. crashkernel_low=size[KMG] - [KNL, x86_64] range under 4G. When crashkernel= is - passed, kernel allocate physical memory region + [KNL, x86_64] range under 4G. When crashkernel_high= is + passed, kernel could allocate physical memory region above 4G, that cause second kernel crash on system that require some amount of low memory, e.g. swiotlb requires at least 64M+32K low memory. Kernel would @@ -613,6 +620,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted. This one let user to specify own low range under 4G for second kernel instead. 0: to disable low allocation. + It will be ignored when crashkernel_high=X is not used + or memory reserved is below 4G. cs89x0_dma= [HW,NET] Format: <dma> |