[PATCH v6 0/8] x86/resctrl: Miscellaneous resctrl features

From: Babu Moger
Date: Wed Jul 19 2023 - 19:21:24 EST


These series adds support few minor features.
1. Support assigning multiple tasks to control/mon groups in one command.
2. Add debug mount option for resctrl interface.
3. Add RMID and CLOSID in resctrl interface when mounted with debug option.
4. Moves the default control group creation during the mount instead of during init.
5. While doing these above changes, found that rftype flags needed some cleanup.
They were named inconsistently. Re-arranged them much more cleanly now and added
few comments. Hope it can help future additions.
---
v6:
Changes since v5:
Moved the default group creation during mount instead of kernel init.
The rdt_root creation moved to rdt_get_tree as suggested by Reinette.
https://lore.kernel.org/lkml/8f68ace7-e05b-ad6d-fa74-5ff8e179aec9@xxxxxxxxx/
Needed to modify rdtgroup_setup_root to take care of this.
Re-arraged the patches to move the default group creation earlier.
Others are mostly text changes and few minor changes.
Patches are based on tip/master commit 1a2945f27157825a561be7840023e3664111ab2f

v5:
Changes since v4:
Moved the default group creation during mount instead of kernel init.
Tried to address most of the comments on commit log. Added more context and details.
Addressed feedback about the patch4. Removed the code changes and only kept the comments.
I am ok to drop patch4. But I will wait for the comment on that.
There were lots of comments. Hope I did not miss anything. Even if I missed, it is
not intentional.

v4: Changes since v3
Addressed comments from Reinette and others.
Removed newline requirement when adding tasks.
Dropped one of the changes on flags. Kept the flag names mostly same.
Changed the names of closid and rmid to ctrl_hw_id and mon_hw_id respectively.
James had some concerns about adding these files. Addressed it by making these
files x86 specific.
Tried to address Reinette's comment on patch 7. But due to current code design
I could not do it exact way. But changed it little bit to make it easy debug
file additions in the future.

v3: Changes since v2
Still waiting for more comments. While waiting, addressed few comments from Fenghua.
Added few more texts in the documentation about multiple tasks assignment feature.
Added pid in last_cmd_status when applicable.
Introduced static resctrl_debug to save the debug option.
Few minor text changes.

v2: Changes since v1
a. Removed the changes to add the task's threads automatically. It required
book keeping to handle the failures and gets complicated. Removed that change
for now.
b. Added -o debug option to mount in debug mode(comment from Fenghua)
c. Added debug files rmid and closid. Stephane wanted to rename them more
generic to accommodate ARM. It kind of loses meaning if is renamed differently.
Kept it same for now. Will change if he feels strong about it.

v5: https://lore.kernel.org/lkml/168564586603.527584.10518315376465080920.stgit@bmoger-ubuntu/
v4: https://lore.kernel.org/lkml/168177435378.1758847.8317743523931859131.stgit@bmoger-ubuntu/
v3: https://lore.kernel.org/lkml/167778850105.1053859.14596357862185564029.stgit@bmoger-ubuntu/
v2: https://lore.kernel.org/lkml/167537433143.647488.9641864719195184123.stgit@bmoger-ubuntu/
v1: https://lore.kernel.org/lkml/167278351577.34228.12803395505584557101.stgit@bmoger-ubuntu/


Babu Moger (8):
x86/resctrl: Add multiple tasks to the resctrl group at once
x86/resctrl: Simplify rftype flag definitions
x86/resctrl: Rename rftype flags for consistency
x86/resctrl: Add comments on RFTYPE flags hierarchy
x86/resctrl: Unwind the errors inside rdt_enable_ctx
x86/resctrl: Move default control group creation during mount
x86/resctrl: Introduce "-o debug" mount option
x86/resctrl: Display hardware ids of resource groups


Documentation/arch/x86/resctrl.rst | 21 ++-
arch/x86/kernel/cpu/resctrl/internal.h | 70 ++++++--
arch/x86/kernel/cpu/resctrl/rdtgroup.c | 217 ++++++++++++++++++-------
3 files changed, 236 insertions(+), 72 deletions(-)

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