[RFC v3 0/3] powerpc/hotplug: Fix affinity assoc for LPAR migration

Michael Bringmann mwb at linux.vnet.ibm.com
Thu May 10 02:12:55 AEST 2018


The migration of LPARs across Power systems affects many attributes
including that of the associativity of memory blocks and CPUs.  The
patches in this set execute when a system is coming up fresh upon a
migration target.  They are intended to,

* Recognize changes to the associativity of memory and CPUs recorded
  in internal data structures when compared to the latest copies in
  the device tree (e.g. ibm,dynamic-memory, ibm,dynamic-memory-v2,
  cpus),
* Recognize changes to the associativity mapping (e.g. ibm,
  associativity-lookup-arrays), locate all assigned memory blocks
  corresponding to each changed row, and readd all such blocks.
* Generate calls to other code layers to reset the data structures
  related to associativity of the CPUs and memory.
* Re-register the 'changed' entities into the target system.
  Re-registration of CPUs and memory blocks mostly entails acting as
  if they have been newly hot-added into the target system.

Signed-off-by: Michael Bringmann <mwb at linux.vnet.ibm.com>

Michael Bringmann (3):
  powerpc migration/drmem: Modify DRMEM code to export more features
  powerpc migration/cpu: Associativity & cpu changes
  powerpc migration/memory: Associativity & memory updates
---
Changes in RFC:
  -- Restructure and rearrange content of patches to co-locate
     similar or related modifications.
  -- Rename pseries_update_drconf_cpu to pseries_update_cpu
  -- Simplify code to update CPU nodes during mobility checks.
     Remove functions to generate extra HP_ELOG messages in favor
     of direct function calls to dlpar_cpu_readd_by_index, or
     dlpar_memory_readd_by_index.
  -- Revise code order in dlpar_cpu_readd_by_index() to present
     more appropriate error codes from underlying layers of the
     implementation.
  -- Add hotplug device lock around all property updates
  -- Schedule all CPU and memory changes due to device-tree updates /
     LPAR mobility as workqueue operations
  -- Export DRMEM accessor functions to parse 'ibm,dynamic-memory-v2'
  -- Export DRMEM functions to provide user copies of LMB array
  -- Compress code using DRMEM accessor functions.
  -- Split topology timer crash fix into new patch.
  -- Modify DRMEM code to replace usages of dt_root_addr_cells, and
     dt_mem_next_cell, as these are only available at first boot.
  -- Correct a bug in DRC index selection for queued operation.



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