To change the resources allocated to a large group of tasks, such as an
application container, a container manager must write all of the tasks'
IDs into the tasks file interface of the new control group. This is
challenging when the container's task list is always changing.

In addition, if the container manager is using monitoring groups to
separately track the bandwidth of containers assigned to the same
control group, when moving a container, it must first move the
container's tasks to the default monitoring group of the new control
group before it can move these tasks into the container's replacement
monitoring group under the destination control group. This is
undesirable because it makes bandwidth usage during the move
unattributable to the correct tasks and resets monitoring event counters
and cache usage information for the group.

Implement the rename operation only for resctrlfs monitor groups to
enable users to move a monitoring group from one control group to
another. This effects a change in resources allocated to all the tasks
in the monitoring group while otherwise leaving the monitoring data
intact.

Signed-off-by: Peter Newman <peternewman@google.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Link: https://lore.kernel.org/r/20230419125015.693566-3-peternewman@google.com

rdtgroup_kn_lock_live() can only release a kernfs reference for a single
file before waiting on the rdtgroup_mutex, limiting its usefulness for
operations on multiple files, such as rename.

Factor the work needed to respectively break and unbreak active
protection on an individual file into rdtgroup_kn_{get,put}().

No functional change.

Signed-off-by: Peter Newman <peternewman@google.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Link: https://lore.kernel.org/r/20230419125015.693566-2-peternewman@google.com

When writing a task id to the "tasks" file in an rdtgroup,
rdtgroup_tasks_write() treats the pid as a number in the current pid
namespace. But when reading the "tasks" file, rdtgroup_tasks_show() shows
the list of global pids from the init namespace, which is confusing and
incorrect.

To be more robust, let the "tasks" file only show pids in the current pid
namespace.

Fixes: e02737d5b826 ("x86/intel_rdt: Add tasks files")
Signed-off-by: Shawn Wang <shawnwang@linux.alibaba.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Acked-by: Reinette Chatre <reinette.chatre@intel.com>
Acked-by: Fenghua Yu <fenghua.yu@intel.com>
Tested-by: Reinette Chatre <reinette.chatre@intel.com>
Link: https://lore.kernel.org/all/20230116071246.97717-1-shawnwang@linux.alibaba.com/

Pull x86 resctrl update from Dave Hansen:
 "Reduce redundant counter reads with resctrl refactoring"

* tag 'x86_cache_for_6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/resctrl: Avoid redundant counter read in __mon_event_count()

Pull driver core updates from Greg KH:
 "Here is the large set of driver core changes for 6.4-rc1.

  Once again, a busy development cycle, with lots of changes happening
  in the driver core in the quest to be able to move "struct bus" and
  "struct class" into read-only memory, a task now complete with these
  changes.

  This will make the future rust interactions with the driver core more
  "provably correct" as well as providing more obvious lifetime rules
  for all busses and classes in the kernel.

  The changes required for this did touch many individual classes and
  busses as many callbacks were changed to take const * parameters
  instead. All of these changes have been submitted to the various
  subsystem maintainers, giving them plenty of time to review, and most
  of them actually did so.

  Other than those changes, included in here are a small set of other
  things:

   - kobject logging improvements

   - cacheinfo improvements and updates

   - obligatory fw_devlink updates and fixes

   - documentation updates

   - device property cleanups and const * changes

   - firwmare loader dependency fixes.

  All of these have been in linux-next for a while with no reported
  problems"

* tag 'driver-core-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (120 commits)
  device property: make device_property functions take const device *
  driver core: update comments in device_rename()
  driver core: Don't require dynamic_debug for initcall_debug probe timing
  firmware_loader: rework crypto dependencies
  firmware_loader: Strip off \n from customized path
  zram: fix up permission for the hot_add sysfs file
  cacheinfo: Add use_arch[|_cache]_info field/function
  arch_topology: Remove early cacheinfo error message if -ENOENT
  cacheinfo: Check cache properties are present in DT
  cacheinfo: Check sib_leaf in cache_leaves_are_shared()
  cacheinfo: Allow early level detection when DT/ACPI info is missing/broken
  cacheinfo: Add arm64 early level initializer implementation
  cacheinfo: Add arch specific early level initializer
  tty: make tty_class a static const structure
  driver core: class: remove struct class_interface * from callbacks
  driver core: class: mark the struct class in struct class_interface constant
  driver core: class: make class_register() take a const *
  driver core: class: mark class_release() as taking a const *
  driver core: remove incorrect comment for device_create*
  MIPS: vpe-cmp: remove module owner pointer from struct class usage.
  ...

Pull documentation updates from Jonathan Corbet:
 "Commit volume in documentation is relatively low this time, but there
  is still a fair amount going on, including:

   - Reorganize the architecture-specific documentation under
     Documentation/arch

     This makes the structure match the source directory and helps to
     clean up the mess that is the top-level Documentation directory a
     bit. This work creates the new directory and moves x86 and most of
     the less-active architectures there.

     The current plan is to move the rest of the architectures in 6.5,
     with the patches going through the appropriate subsystem trees.

   - Some more Spanish translations and maintenance of the Italian
     translation

   - A new "Kernel contribution maturity model" document from Ted

   - A new tutorial on quickly building a trimmed kernel from Thorsten

  Plus the usual set of updates and fixes"

* tag 'docs-6.4' of git://git.lwn.net/linux: (47 commits)
  media: Adjust column width for pdfdocs
  media: Fix building pdfdocs
  docs: clk: add documentation to log which clocks have been disabled
  docs: trace: Fix typo in ftrace.rst
  Documentation/process: always CC responsible lists
  docs: kmemleak: adjust to config renaming
  ELF: document some de-facto PT_* ABI quirks
  Documentation: arm: remove stih415/stih416 related entries
  docs: turn off "smart quotes" in the HTML build
  Documentation: firmware: Clarify firmware path usage
  docs/mm: Physical Memory: Fix grammar
  Documentation: Add document for false sharing
  dma-api-howto: typo fix
  docs: move m68k architecture documentation under Documentation/arch/
  docs: move parisc documentation under Documentation/arch/
  docs: move ia64 architecture docs under Documentation/arch/
  docs: Move arc architecture docs under Documentation/arch/
  docs: move nios2 documentation under Documentation/arch/
  docs: move openrisc documentation under Documentation/arch/
  docs: move superh documentation under Documentation/arch/
  ...

We need the fixes in here for testing, as well as the driver core
changes for documentation updates to build on.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Move the x86 documentation under Documentation/arch/ as a way of cleaning
up the top-level directory and making the structure of our docs more
closely match the structure of the source directories it describes.

All in-kernel references to the old paths have been updated.

Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: linux-arch@vger.kernel.org
Cc: x86@kernel.org
Cc: Borislav Petkov <bp@alien8.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/lkml/20230315211523.108836-1-corbet@lwn.net/
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

The module pointer in class_create() never actually did anything, and it
shouldn't have been requred to be set as a parameter even if it did
something.  So just remove it and fix up all callers of the function in
the kernel tree at the same time.

Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Acked-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Link: https://lore.kernel.org/r/20230313181843.1207845-4-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

__mon_event_count() does the per-RMID, per-domain work for
user-initiated event count reads and the initialization of new monitor
groups.

In the initialization case, after resctrl_arch_reset_rmid() calls
__rmid_read() to record an initial count for a new monitor group, it
immediately calls resctrl_arch_rmid_read(). This re-read of the hardware
counter is unnecessary and the following computations are ignored by the
caller during initialization.

Following return from resctrl_arch_reset_rmid(), just clear the
mbm_state and return. This involves moving the mbm_state lookup into the
rr->first case, as it's not needed for regular event count reads: the
QOS_L3_OCCUP_EVENT_ID case was redundant with the accumulating logic at
the end of the function.

Signed-off-by: Peter Newman <peternewman@google.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Tested-by: Babu Moger <babu.moger@amd.com>
Link: https://lore.kernel.org/all/20221220164132.443083-2-peternewman%40google.com