[v4,0/3] Subject: x86/resctrl: Implement rename to help move containers' tasks

Message ID 20230308131452.383914-1-peternewman@google.com
Headers
Series Subject: x86/resctrl: Implement rename to help move containers' tasks |

Message

Peter Newman March 8, 2023, 1:14 p.m. UTC
  Hi Reinette, Fenghua,

This patch series implements the solution Reinette suggested in the
earlier RFD thread[1] for the problem of moving a container's tasks to a
different control group on systems that don't provide enough CLOSIDs to
give every container its own control group.

This patch series assumes that a MON group's CLOSID can simply be
changed to that of a new parent CTRL_MON group. This is allowed on Intel
and AMD, but not MPAM implementations. While we (Google) only foresee
needing this functionality on Intel and AMD systems, this series should
hopefully be a good starting point for supporting MPAM.

Thanks!
-Peter

Updates:

v4:
 - rebase to v6.2
 - commit message updates suggested by Reinette
 - replace rdt_move_one_task() patch with rdt_move_group_tasks() filter
   function patch
 - prevent rename on files or renaming to "mon_groups"
 - optimize simple rename case
 - disallow renaming groups with non-empty cpumask
 - ensure source is a proper MON group directory
 - fix missing rdtgrp->closid update
 - add more last_command_status output

v3: use revised task CLOSID/RMID update IPI sync method from [3]
v2: reworded change logs based on what I've learned from review comments
    in another patch series[2]

[v1] https://lore.kernel.org/lkml/20221115154515.952783-1-peternewman@google.com/
[v2] https://lore.kernel.org/lkml/20221129120149.1035444-1-peternewman@google.com/
[v3] https://lore.kernel.org/lkml/20230125101334.1069060-1-peternewman@google.com/

[1] https://lore.kernel.org/lkml/7b09fb62-e61a-65b9-a71e-ab725f527ded@intel.com/
[2] https://lore.kernel.org/lkml/54e50a9b-268f-2020-f54c-d38312489e2f@intel.com/
[3] https://lore.kernel.org/lkml/20221220161123.432120-1-peternewman@google.com/

Peter Newman (3):
  x86/resctrl: Factor rdtgroup lock for multi-file ops
  x86/resctrl: Parameterize rdt_move_group_tasks() task matching
  x86/resctrl: Implement rename op for mon groups

 arch/x86/kernel/cpu/resctrl/rdtgroup.c | 196 ++++++++++++++++++++++---
 1 file changed, 174 insertions(+), 22 deletions(-)


base-commit: c9c3395d5e3dcc6daee66c6908354d47bf98cb0c