kernel_optimize_test/arch/powerpc/kexec
Sourabh Jain ea21eaea7f powerpc: Set crashkernel offset to mid of RMA region
[ Upstream commit 7c5ed82b800d8615cdda00729e7b62e5899f0b13 ]

On large config LPARs (having 192 and more cores), Linux fails to boot
due to insufficient memory in the first memblock. It is due to the
memory reservation for the crash kernel which starts at 128MB offset of
the first memblock. This memory reservation for the crash kernel doesn't
leave enough space in the first memblock to accommodate other essential
system resources.

The crash kernel start address was set to 128MB offset by default to
ensure that the crash kernel get some memory below the RMA region which
is used to be of size 256MB. But given that the RMA region size can be
512MB or more, setting the crash kernel offset to mid of RMA size will
leave enough space for the kernel to allocate memory for other system
resources.

Since the above crash kernel offset change is only applicable to the LPAR
platform, the LPAR feature detection is pushed before the crash kernel
reservation. The rest of LPAR specific initialization will still
be done during pseries_probe_fw_features as usual.

This patch is dependent on changes to paca allocation for boot CPU. It
expect boot CPU to discover 1T segment support which is introduced by
the patch posted here:
https://lists.ozlabs.org/pipermail/linuxppc-dev/2022-January/239175.html

Reported-by: Abdul haleem <abdhalee@linux.vnet.ibm.com>
Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220204085601.107257-1-sourabhjain@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2022-04-13 21:00:56 +02:00
..
core_32.c
core_64.c powerpc/book3s64/keys/kuap: Reset AMR/IAMR values on kexec 2020-07-20 22:57:59 +10:00
core.c powerpc: Set crashkernel offset to mid of RMA region 2022-04-13 21:00:56 +02:00
crash.c powerpc/crash: Use NMI context for printk when starting to crash 2020-06-02 20:59:07 +10:00
elf_64.c powerpc/kexec_file: fix FDT size estimation for kdump kernel 2021-03-04 11:38:39 +01:00
file_load_64.c powerpc/kexec_file: Use current CPU info while setting up FDT 2021-05-11 14:47:35 +02:00
file_load.c powerpc/kexec_file: Prepare elfcore header for crashing kernel 2020-07-29 23:47:54 +10:00
ima.c
Makefile powerpc/kexec_file: Add helper functions for getting memory ranges 2020-07-29 23:47:53 +10:00
ranges.c powerpc/kexec_file: Avoid stomping memory used by special regions 2020-07-29 23:47:53 +10:00
relocate_32.S