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[v6,0/7] SRAT/CEDT fixes and updates

Message ID 20240430092200.2335887-1-rrichter@amd.com
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Series SRAT/CEDT fixes and updates | expand

Message

Robert Richter April 30, 2024, 9:21 a.m. UTC 
Some fixes and updates for SRAT/CEDT parsing code. Patches can be
applied individually and are independent.

First patch fixes a page fault during boot (fix as suggested by Dan).

Patches 2 to 4 remove architectural code no longer needed.

Patches 5 to 7 add diagnostic printouts for CEDT.

Changelog:

v6:
 * rebased onto cxl/fixes
 * fixed 0day build errors in patch #1:
   https://github.com/intel-lab-lkp/linux/commits/Robert-Richter/x86-numa-Fix-SRAT-lookup-of-CFMWS-ranges-with-numa_fill_memblks/20240429-205337

v5:
 * dropped: "x86/numa: Fix SRAT lookup of CFMWS ranges with
   numa_fill_memblks()"
 * added: "ACPI/NUMA: Return memblk modification state from
   numa_fill_memblks()"
 * conditionally print CEDT extended memblks

v4:
 * updated SOB chains and desription
 * added patch "x86/numa: Remove numa_fill_memblks() from sparsemem.h
   using __weak"
 * Reordered patches to move CEDT table printout as an option at the
   end
 * split print table patch and added: "ACPI/NUMA: Add log messages for
   memory ranges found in CEDT"

v3:
 * Rebased onto v6.9-rc1
 * Fixing x86 build error in sparsemem.h [Dan/Alison]
 * Added CEDT node info [Alison]
 * Use pr_debug() for table output [Dan]
 * Refactoring split in 3 patches [Dan]
 * Fixed performance regression introduced [kbot]
 * Fixed checkpatch issues [Dan]

Robert Richter (7):
  x86/numa: Fix SRAT lookup of CFMWS ranges with numa_fill_memblks()
  ACPI/NUMA: Remove architecture dependent remainings
  ACPI/NUMA: Squash acpi_numa_slit_init() into acpi_parse_slit()
  ACPI/NUMA: Squash acpi_numa_memory_affinity_init() into
    acpi_parse_memory_affinity()
  ACPI/NUMA: Return memblk modification state from numa_fill_memblks()
  ACPI/NUMA: Add log messages for memory ranges found in CEDT
  ACPI/NUMA: Print CXL Early Discovery Table (CEDT)

 arch/x86/include/asm/sparsemem.h |   2 -
 arch/x86/mm/numa.c               |  37 +++---
 drivers/acpi/numa/srat.c         | 207 +++++++++++++++++++++++--------
 include/linux/acpi.h             |   5 -
 include/linux/numa.h             |   7 +-
 5 files changed, 176 insertions(+), 82 deletions(-)


base-commit: 5d211c7090590033581175d6405ae40917ca3a06

Comments

Robert Richter May 2, 2024, 12:11 p.m. UTC | #1 
On 30.04.24 09:16:56, Alison Schofield wrote:
> On Tue, Apr 30, 2024 at 11:21:54AM +0200, Robert Richter wrote:
> > For configurations that have the kconfig option NUMA_KEEP_MEMINFO
> > disabled numa_fill_memblks() only returns with NUMA_NO_MEMBLK (-1).
> > SRAT lookup fails then because an existing SRAT memory range cannot be
> > found for a CFMWS address range. This causes the addition of a
> > duplicate numa_memblk with a different node id and a subsequent page
> > fault and kernel crash during boot.
> > 
> > Fix this by making numa_fill_memblks() always available regardless of
> > NUMA_KEEP_MEMINFO.
> > 
> > The fix also removes numa_fill_memblks() from sparsemem.h using
> > __weak.
> > 
> > From Dan:
> > 
> > """
> > It just feels like numa_fill_memblks() has absolutely no business being
> > defined in arch/x86/include/asm/sparsemem.h.
> > 
> > The only use for numa_fill_memblks() is to arrange for NUMA nodes to be
> > applied to memory ranges hot-onlined by the CXL driver.
> > 
> > It belongs right next to numa_add_memblk(), and I suspect
> > arch/x86/include/asm/sparsemem.h was only chosen to avoid figuring out
> > what to do about the fact that linux/numa.h does not include asm/numa.h
> > and that all implementations either provide numa_add_memblk() or select
> > the generic implementation.
> > 
> > So I would prefer that this do the proper fix and get
> > numa_fill_memblks() completely out of the sparsemem.h path.
> > 
> > Something like the following which boots for me.
> > """
> > 
> > Note that the issue was initially introduced with [1]. But since
> > phys_to_target_node() was originally used that returned the valid node
> > 0, an additional numa_memblk was not added. Though, the node id was
> > wrong too, a message is seen then in the logs:
> > 
> >  kernel/numa.c:  pr_info_once("Unknown target node for memory at 0x%llx, assuming node 0\n",
> > 
> > [1] commit fd49f99c1809 ("ACPI: NUMA: Add a node and memblk for each
> >     CFMWS not in SRAT")
> > 
> 
> For the commit log above -
> Perhaps the Dan quote can be reduced to a note about the implementation
> choice. Folks can look up the Lore thread if history is needed.
> 
> For the code -
> Reviewed-by: Alison Schofield <alison.schofield@intel.com>

Adjusted description, thanks.

-Robert