linux_dsm_epyc7002/Documentation/x86
Dan Williams cc9aec03e5 x86/numa_emulation: Introduce uniform split capability
The current NUMA emulation capabilities for splitting System RAM by a
fixed size or by a set number of nodes may result in some nodes being
larger than others. The implementation prioritizes establishing a
minimum usable memory size over satisfying the requested number of NUMA
nodes.

Introduce a uniform split capability that evenly partitions each
physical NUMA node into N emulated nodes. For example numa=fake=3U
creates 6 emulated nodes total on a system that has 2 physical nodes.

This capability is useful for debugging and evaluating platform
memory-side-cache capabilities as described by the ACPI HMAT (see
5.2.27.5 Memory Side Cache Information Structure in ACPI 6.2a)

Compare numa=fake=6 that results in only 5 nodes being created against
numa=fake=3U which takes the 2 physical nodes and evenly divides them.

numa=fake=6
available: 5 nodes (0-4)
node 0 cpus: 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38
node 0 size: 2648 MB
node 0 free: 2443 MB
node 1 cpus: 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39
node 1 size: 2672 MB
node 1 free: 2442 MB
node 2 cpus: 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38
node 2 size: 5291 MB
node 2 free: 5278 MB
node 3 cpus: 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39
node 3 size: 2677 MB
node 3 free: 2665 MB
node 4 cpus: 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39
node 4 size: 2676 MB
node 4 free: 2663 MB
node distances:
node   0   1   2   3   4
  0:  10  20  10  20  20
  1:  20  10  20  10  10
  2:  10  20  10  20  20
  3:  20  10  20  10  10
  4:  20  10  20  10  10

numa=fake=3U
available: 6 nodes (0-5)
node 0 cpus: 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38
node 0 size: 2900 MB
node 0 free: 2637 MB
node 1 cpus: 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38
node 1 size: 3023 MB
node 1 free: 3012 MB
node 2 cpus: 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38
node 2 size: 2015 MB
node 2 free: 2004 MB
node 3 cpus: 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39
node 3 size: 2704 MB
node 3 free: 2522 MB
node 4 cpus: 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39
node 4 size: 2709 MB
node 4 free: 2698 MB
node 5 cpus: 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39
node 5 size: 2612 MB
node 5 free: 2601 MB
node distances:
node   0   1   2   3   4   5
  0:  10  10  10  20  20  20
  1:  10  10  10  20  20  20
  2:  10  10  10  20  20  20
  3:  20  20  20  10  10  10
  4:  20  20  20  10  10  10
  5:  20  20  20  10  10  10

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/153089328617.27680.14930758266174305832.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-06 18:48:58 +02:00
..
i386 doc: spelling error changes 2014-05-05 15:32:05 +02:00
x86_64 x86/numa_emulation: Introduce uniform split capability 2018-07-06 18:48:58 +02:00
00-INDEX Documentation: Fix early-microcode.txt references after file rename 2018-03-27 09:51:23 +02:00
amd-memory-encryption.txt Documentation/x86: Add AMD Secure Encrypted Virtualization (SEV) description 2017-11-07 15:35:54 +01:00
boot.txt docs: fix locations of several documents that got moved 2016-10-24 08:12:35 -02:00
earlyprintk.txt doc: spelling error changes 2014-05-05 15:32:05 +02:00
entry_64.txt x86/asm/entry/64: Update path names 2015-07-02 11:08:50 +02:00
exception-tables.txt x86/mm: Expand the exception table logic to allow new handling options 2016-02-18 09:21:46 +01:00
intel_mpx.txt x86/Documentation: Fix various typos in Documentation/x86/ files 2016-07-01 10:00:10 +02:00
intel_rdt_ui.txt x86/intel_rdt/mba_sc: Documentation for MBA software controller(mba_sc) 2018-05-19 13:16:42 +02:00
kernel-stacks Documentation/x86: Rename IRQSTACKSIZE to IRQ_STACK_SIZE 2015-08-24 11:42:41 -06:00
microcode.txt firmware: Fix up docs referring to FIRMWARE_IN_KERNEL 2018-01-25 12:46:30 +01:00
mtrr.txt x86/mm/mtrr: Remove kernel internal MTRR interfaces: unexport mtrr_add() and mtrr_del() 2015-08-28 10:09:28 +02:00
orc-unwinder.txt x86/unwind: Rename unwinder config options to 'CONFIG_UNWINDER_*' 2017-10-14 10:12:12 +02:00
pat.txt x86/pat: Document the PAT initialization sequence 2016-03-29 12:23:27 +02:00
protection-keys.txt x86/pkeys: Update documentation about availability 2017-11-21 09:34:52 +01:00
pti.txt x86/pti: Document fix wrong index 2018-01-19 16:31:29 +01:00
tlb.txt x86/Documentation: Fix various typos in Documentation/x86/ files 2016-07-01 10:00:10 +02:00
topology.txt x86/topology: Fix function name in documentation 2018-02-23 08:40:12 +01:00
usb-legacy-support.txt x86: doc: move x86-generic documentation from Doc/x86/i386 2008-07-22 15:34:38 -04:00
zero-page.txt Merge branch 'linus' into WIP.x86/boot, to fix up conflicts and to pick up updates 2017-03-01 09:02:26 +01:00