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b5667d13be
The kexec purgatory has to run in real mode. Only the first memory block maybe accessible in real mode. And, unlike the case with panic kernel, no memory is set aside for regular kexec load. Another thing to note is, the memory for crashkernel is reserved at an offset of 128MB. So, when crashkernel memory is reserved, the memory ranges to load kexec segments shrink further as the generic code only looks for memblock free memory ranges and in all likelihood only a tiny bit of memory from 0 to 128MB would be available to load kexec segments. With kdump being used by default in general, kexec file load is likely to fail almost always. This can be fixed by changing the memory hole lookup logic for regular kexec to use the same method as kdump. This would mean that most kexec segments will overlap with crashkernel memory region. That should still be ok as the pages, whose destination address isn't available while loading, are placed in an intermediate location till a flush to the actual destination address happens during kexec boot sequence. Signed-off-by: Hari Bathini <hbathini@linux.ibm.com> Tested-by: Pingfan Liu <piliu@redhat.com> Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/159602302326.575379.14038896654942043093.stgit@hbathini
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.