| Message ID | 20220227030717.1464-6-thunder.leizhen@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | support reserving crashkernel above 4G on arm64 kdump | expand |
On 02/27/22 at 11:07am, Zhen Lei wrote: > Now arm64 has added support for "crashkernel=X,high" and > "crashkernel=Y,low", and implements "crashkernel=X[@offset]" in the > same way as x86. So update the Documentation. > > Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> Looks good to me, thx. Acked-by: Baoquan He <bhe@redhat.com> > --- > Documentation/admin-guide/kernel-parameters.txt | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) > > diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt > index f5a27f067db9ed9..63098786c93828c 100644 > --- a/Documentation/admin-guide/kernel-parameters.txt > +++ b/Documentation/admin-guide/kernel-parameters.txt > @@ -789,7 +789,7 @@ > memory region [offset, offset + size] for that kernel > image. If '@offset' is omitted, then a suitable offset > is selected automatically. > - [KNL, X86-64] Select a region under 4G first, and > + [KNL, X86-64, ARM64] Select a region under 4G first, and > fall back to reserve region above 4G when '@offset' > hasn't been specified. > See Documentation/admin-guide/kdump/kdump.rst for further details. > @@ -802,20 +802,20 @@ > Documentation/admin-guide/kdump/kdump.rst for an example. > > crashkernel=size[KMG],high > - [KNL, X86-64] range could be above 4G. Allow kernel > + [KNL, X86-64, ARM64] 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=size[KMG],low > - [KNL, X86-64] range under 4G. When crashkernel=X,high > + [KNL, X86-64, ARM64] range under 4G. When crashkernel=X,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, also enough extra > low memory is needed to make sure DMA buffers for 32-bit > - devices won't run out. Kernel would try to allocate at > + devices won't run out. Kernel would try to allocate > at least 256M below 4G automatically. > This one let user to specify own low range under 4G > for second kernel instead. > -- > 2.25.1 >
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index f5a27f067db9ed9..63098786c93828c 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -789,7 +789,7 @@ memory region [offset, offset + size] for that kernel image. If '@offset' is omitted, then a suitable offset is selected automatically. - [KNL, X86-64] Select a region under 4G first, and + [KNL, X86-64, ARM64] Select a region under 4G first, and fall back to reserve region above 4G when '@offset' hasn't been specified. See Documentation/admin-guide/kdump/kdump.rst for further details. @@ -802,20 +802,20 @@ Documentation/admin-guide/kdump/kdump.rst for an example. crashkernel=size[KMG],high - [KNL, X86-64] range could be above 4G. Allow kernel + [KNL, X86-64, ARM64] 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=size[KMG],low - [KNL, X86-64] range under 4G. When crashkernel=X,high + [KNL, X86-64, ARM64] range under 4G. When crashkernel=X,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, also enough extra low memory is needed to make sure DMA buffers for 32-bit - devices won't run out. Kernel would try to allocate at + devices won't run out. Kernel would try to allocate at least 256M below 4G automatically. This one let user to specify own low range under 4G for second kernel instead.
Now arm64 has added support for "crashkernel=X,high" and "crashkernel=Y,low", and implements "crashkernel=X[@offset]" in the same way as x86. So update the Documentation. Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> --- Documentation/admin-guide/kernel-parameters.txt | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)