Commit Graph

9 Commits

Author SHA1 Message Date
Fenghua Yu 0dd2d7494c x86/intel_rdt: Show bitmask of shareable resource with other executing units
CPUID.(EAX=0x10, ECX=res#):EBX[31:0] reports a bit mask for a resource.
Each set bit within the length of the CBM indicates the corresponding
unit of the resource allocation may be used by other entities in the
platform (e.g. an integrated graphics engine or hardware units outside
the processor core and have direct access to the resource). Each
cleared bit within the length of the CBM indicates the corresponding
allocation unit can be configured to implement a priority-based
allocation scheme without interference with other hardware agents in
the system. Bits outside the length of the CBM are reserved.

More details on the bit mask are described in x86 Software Developer's
Manual.

The bitmask is shown in "info" directory for each resource. It's
up to user to decide how to use the bitmask within a CBM in a partition
to share or isolate a resource with other executing units.

Suggested-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: ravi.v.shankar@intel.com
Cc: peterz@infradead.org
Cc: eranian@google.com
Cc: ak@linux.intel.com
Cc: davidcc@google.com
Cc: vikas.shivappa@linux.intel.com
Link: http://lkml.kernel.org/r/20170725223904.12996-1-tony.luck@intel.com
2017-08-01 22:41:30 +02:00
Vikas Shivappa 1640ae9471 x86/intel_rdt/cqm: Documentation for resctrl based RDT Monitoring
Add a description of resctrl based RDT(resource director technology)
monitoring extension and its usage.

[Tony: Added descriptions for how monitoring and allocation are measured
and some cleanups]

Signed-off-by: Vikas Shivappa <vikas.shivappa@linux.intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: ravi.v.shankar@intel.com
Cc: fenghua.yu@intel.com
Cc: peterz@infradead.org
Cc: eranian@google.com
Cc: vikas.shivappa@intel.com
Cc: ak@linux.intel.com
Cc: davidcc@google.com
Cc: reinette.chatre@intel.com
Link: http://lkml.kernel.org/r/1501017287-28083-3-git-send-email-vikas.shivappa@linux.intel.com
2017-08-01 22:41:19 +02:00
Xiaochen Shen fb8fb46c56 x86/intel_rdt: Fix a typo in Documentation
Example 3 contains a typo:

"C0" in "# echo C0 > p0/cpus" is wrong because it specifies core
6-7 instead of wanted core 4-7.

Correct this typo to avoid confusion.

Signed-off-by: Xiaochen Shen <xiaochen.shen@intel.com>
Acked-by: Fenghua Yu <fenghua.yu@intel.com>
Cc: vikas.shivappa@linux.intel.com
Cc: tony.luck@intel.com
Link: http://lkml.kernel.org/r/1493781356-24229-1-git-send-email-xiaochen.shen@intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-05-09 09:41:42 +02:00
Vikas Shivappa a9cad3d4f0 Documentation, x86: Intel Memory bandwidth allocation
Update the 'intel_rdt_ui' documentation to have Memory bandwidth(b/w)
allocation interface usage.

Signed-off-by: Vikas Shivappa <vikas.shivappa@linux.intel.com>
Cc: ravi.v.shankar@intel.com
Cc: tony.luck@intel.com
Cc: fenghua.yu@intel.com
Cc: vikas.shivappa@intel.com
Link: http://lkml.kernel.org/r/1491611637-20417-2-git-send-email-vikas.shivappa@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-04-14 16:10:07 +02:00
Jiri Olsa 4ffa3c977b x86/intel_rdt: Add cpus_list rdtgroup file
The resource control filesystem provides only a bitmask based cpus file for
assigning CPUs to a resource group. That's cumbersome with large cpumasks
and non-intuitive when modifying the file from the command line.

Range based cpu lists are commonly used along with bitmask based cpu files
in various subsystems throughout the kernel.

Add 'cpus_list' file which is CPU range based.

  # cd /sys/fs/resctrl/
  # echo 1-10 > krava/cpus_list
  # cat krava/cpus_list
  1-10
  # cat krava/cpus
  0007fe
  # cat cpus
  fffff9
  # cat cpus_list
  0,3-23

[ tglx: Massaged changelog and replaced "bitmask lists" by "CPU ranges" ]

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Shaohua Li <shli@fb.com>
Link: http://lkml.kernel.org/r/20170410145232.GF25354@krava
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-04-10 19:10:25 +02:00
Tony Luck c4026b7b95 x86/intel_rdt: Implement "update" mode when writing schemata file
The schemata file can have multiple lines and it is cumbersome to update
all lines.

Remove code that requires that the user provides values for every resource
(in the right order).  If the user provides values for just a few
resources, update them and leave the rest unchanged.

Side benefit: we now check which values were updated and only send IPIs to
cpus that actually have updates.

Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Vikas Shivappa <vikas.shivappa@linux.intel.com>
Tested-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Cc: ravi.v.shankar@intel.com
Cc: fenghua.yu@intel.com
Cc: peterz@infradead.org
Cc: vikas.shivappa@intel.com
Cc: h.peter.anvin@intel.com
Link: http://lkml.kernel.org/r/1491255857-17213-3-git-send-email-vikas.shivappa@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-04-05 17:22:31 +02:00
Marcelo Tosatti 3c2a769de7 Documentation, x86, resctrl: Recommend locking for resctrlfs
Concurrent write or read/write access from applications to the resctrlfs
directory can result in incorrect readouts or setups.

Recommend a standard locking scheme for applications to use.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Link: http://lkml.kernel.org/r/20161214170835.GA16924@amt.cnet
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-12-15 14:44:27 +01:00
Thomas Gleixner 458b0d6e75 x86/intel_rdt: Add info files to Documentation
The content of the directories and files in the info directory of the
resctrl filesystem are not documented.

Add the missing bits and pieces.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Shaohua Li <shli@fb.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Tony Luck <tony.luck@intel.com>
2016-11-07 12:20:53 +01:00
Fenghua Yu f20e578928 Documentation, x86: Documentation for Intel resource allocation user interface
The documentation describes user interface of how to allocate resource
in Intel RDT.

Please note that the documentation covers generic user interface. Current
patch set code only implemente CAT L3. CAT L2 code will be sent later.

[ tglx: Added cpu example ]

Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Cc: "Ravi V Shankar" <ravi.v.shankar@intel.com>
Cc: "Tony Luck" <tony.luck@intel.com>
Cc: "Shaohua Li" <shli@fb.com>
Cc: "Sai Prakhya" <sai.praneeth.prakhya@intel.com>
Cc: "Peter Zijlstra" <peterz@infradead.org>
Cc: "Stephane Eranian" <eranian@google.com>
Cc: "Dave Hansen" <dave.hansen@intel.com>
Cc: "David Carrillo-Cisneros" <davidcc@google.com>
Cc: "Nilay Vaish" <nilayvaish@gmail.com>
Cc: "Vikas Shivappa" <vikas.shivappa@linux.intel.com>
Cc: "Ingo Molnar" <mingo@elte.hu>
Cc: "Borislav Petkov" <bp@suse.de>
Cc: "H. Peter Anvin" <h.peter.anvin@intel.com>
Link: http://lkml.kernel.org/r/1477692289-37412-2-git-send-email-fenghua.yu@intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-10-30 19:10:13 -06:00