Memory hotplug is leading to hash page table calls, even on radix:
...
arch_add_memory
create_section_mapping
htab_bolt_mapping
BUG_ON(!ppc_md.hpte_insert);
To fix, refactor {create,remove}_section_mapping() into hash__ and radix__
variants. Implement the radix versions by borrowing from existing vmemmap
and x86 code.
This passes basic verification of plugging and removing memory, but this
stuff is tricky and I'd appreciate extra scrutiny of the series for
correctness--in particular, the adaptation of remove_pagetable() from x86.
/* changelog */
v3:
* Port remove_pagetable() et al. from x86 for unmapping.
* [RFC] -> [PATCH]
v2:
* https://lkml.kernel.org/r/1471449083-15931-1-git-send-email-arbab@linux.vnet.ibm.com
* Do not simply fall through to vmemmap_{create,remove}_mapping(). As Aneesh
and Michael pointed out, they are tied to CONFIG_SPARSEMEM_VMEMMAP and only
did what I needed by luck anyway.
v1:
* https://lkml.kernel.org/r/1466699962-22412-1-git-send-email-arbab@linux.vnet.ibm.com
Reza Arbab (5):
powerpc/mm: set the radix linear page mapping size
powerpc/mm: refactor {create,remove}_section_mapping()
powerpc/mm: add radix__create_section_mapping()
powerpc/mm: add radix__remove_section_mapping()
powerpc/mm: unstub radix__vmemmap_remove_mapping()
arch/powerpc/include/asm/book3s/64/hash.h | 5 +
arch/powerpc/include/asm/book3s/64/radix.h | 5 +
arch/powerpc/mm/hash_utils_64.c | 4 +-
arch/powerpc/mm/pgtable-book3s64.c | 18 +++
arch/powerpc/mm/pgtable-radix.c | 207 ++++++++++++++++++++++++++++-
5 files changed, 236 insertions(+), 3 deletions(-)
--
1.8.3.1