linux/Documentation/x86
Fenghua Yu 29b6bd41ee x86/resctrl: Enable user to view thread or core throttling mode
Early Intel hardware implementations of Memory Bandwidth Allocation (MBA)
could only control bandwidth at the processor core level. This meant that
when two processes with different bandwidth allocations ran simultaneously
on the same core the hardware had to resolve this difference. It did so by
applying the higher throttling value (lower bandwidth) to both processes.

Newer implementations can apply different throttling values to each
thread on a core.

Introduce a new resctrl file, "thread_throttle_mode", on Intel systems
that shows to the user how throttling values are allocated, per-core or
per-thread.

On systems that support per-core throttling, the file will display "max".
On newer systems that support per-thread throttling, the file will display
"per-thread".

AMD confirmed in [1] that AMD bandwidth allocation is already at thread
level but that the AMD implementation does not use a memory delay
throttle mode. So to avoid confusion the thread throttling mode would be
UNDEFINED on AMD systems and the "thread_throttle_mode" file will not be
visible.

Originally-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Link: https://lkml.kernel.org/r/1598296281-127595-3-git-send-email-fenghua.yu@intel.com
Link: [1] https://lore.kernel.org/lkml/18d277fd-6523-319c-d560-66b63ff606b8@amd.com
2020-08-26 17:53:22 +02:00
..
i386 Documentation: x86: convert i386/IO-APIC.txt to reST 2019-05-08 14:34:11 -06:00
x86_64 It's been a busy cycle for documentation - hopefully the busiest for a 2020-08-04 22:47:54 -07:00
amd-memory-encryption.rst Documentation: x86: convert amd-memory-encryption.txt to reST 2019-05-08 14:34:10 -06:00
boot.rst x86: Add support for ZSTD compressed kernel 2020-07-31 11:49:09 +02:00
earlyprintk.rst Documentation: x86: earlyprintk: drop doubled words 2020-07-13 09:47:38 -06:00
entry_64.rst Documentation: x86: convert entry_64.txt to reST 2019-05-08 14:34:09 -06:00
exception-tables.rst Merge branch 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2020-03-31 11:04:05 -07:00
index.rst docs: remove MPX from the x86 toc 2020-02-25 03:10:22 -07:00
intel_txt.rst docs: x86: move two x86-specific files to x86 arch dir 2019-07-15 11:03:01 -03:00
intel-iommu.rst docs: prevent warnings due to autosectionlabel 2020-03-20 17:01:29 -06:00
kernel-stacks.rst Some late arriving documentation changes. In particular, this contains the 2019-05-10 13:24:53 -04:00
mds.rst x86/speculation/mds: Improve CPU buffer clear documentation 2019-05-16 09:05:12 +02:00
microcode.rst Documentation: x86: convert microcode.txt to reST 2019-05-08 14:34:11 -06:00
mtrr.rst Documentation: x86: convert mtrr.txt to reST 2019-05-08 14:34:10 -06:00
orc-unwinder.rst Documentation: x86: convert orc-unwinder.txt to reST 2019-05-08 14:34:11 -06:00
pat.rst remove ioremap_nocache and devm_ioremap_nocache 2020-01-06 09:45:59 +01:00
pti.rst Documentation: x86: convert pti.txt to reST 2019-05-08 14:34:10 -06:00
resctrl_ui.rst x86/resctrl: Enable user to view thread or core throttling mode 2020-08-26 17:53:22 +02:00
tlb.rst Documentation: x86: convert tlb.txt to reST 2019-05-08 14:34:10 -06:00
topology.rst docs: admin-guide: add a series of orphaned documents 2019-07-15 11:03:02 -03:00
tsx_async_abort.rst x86/speculation/taa: Add documentation for TSX Async Abort 2019-10-28 08:37:00 +01:00
usb-legacy-support.rst Documentation: x86: convert usb-legacy-support.txt to reST 2019-05-08 14:34:11 -06:00
zero-page.rst Documentation: x86: convert zero-page.txt to reST 2019-05-08 14:34:10 -06:00