Re: [PATCH v2 00/35] x86/resctrl: Move the resctrl filesystem code to /fs/resctrl

[Peter Newman <peternewman@google.com>]

Hi Dave (and James),

On Fri, Apr 26, 2024 at 8:05 AM Dave Martin <Dave.Martin@arm.com> wrote:
>
> Hi all,
>
> This is a respin of the resctrl refactoring series described below,
> addressing review feedback.  Many thanks to those to responded with
> feedback on the v1 series [2].
>
> See Notes and FYIs in the individual patches for details on the changes
> and outstanding issues.
>
>
> This series has not been rebased since the v1 posting, and remains
> based on the following upstream commit:
>
> commit 23956900041d968f9ad0f30db6dede4daccd7aa9
> Merge tag 'v6.9-rc-smb3-server-fixes' of git://git.samba.org/ksmbd
>
> The actual code changes against v1 are few in number and rather spread
> around.  For reviewer convenience, a diff against v1 is appended to
> this cover letter.
>
> Due to the limited code changes, this series has *not* received any
> additional runtime testing over than done for v1 (other than build
> bisect testing).
>
> Cheers
> ---Dave
>
>
> [2] v1 series:
> [PATCH v1 00/31] x86/resctrl: Move the resctrl filesystem code to /fs/resctrl
> https://lore.kernel.org/all/20240321165106.31602-1-james.morse@arm.com/
>
> --8<-- Original blurb
>
> This is the final series that allows other architectures to implement resctrl.
> The last patch just moves the code, and its a bit of a monster. I don't expect
> that to get merged as part of this series - we should wait for it to make
> less impact on other series. It's included here to show what gets moved, and
> that structures/function-prototypes have the right visibility.
>
> Otherwise this series renames functions and moves code around. With the
> exception of invalid configurations for the configurable-events, there should
> be no changes in behaviour caused by this series.
>
> The driving pattern is to make things like struct rdtgroup private to resctrl.
> Features like pseudo-lock aren't going to work on arm64, the ability to disable
> it at compile time is added.
>
> After this, I can start posting the MPAM driver to make use of resctrl on arm64.
> (What's MPAM? See the cover letter of the first series. [1])
>
> This series is based on Linus' commit 23956900041d and can be retrieved from:
> https://git.kernel.org/pub/scm/linux/kernel/git/morse/linux.git
> mpam/move_to_fs/v1
>
> Sorry for the mid-merge window base, I'm away for a few weeks - this should
> rebase trivially onto rc1.
>
> As ever - bugs welcome,
> Thanks,
>
> James
>
> [1] https://lore.kernel.org/lkml/20201030161120.227225-1-james.morse@arm.com/
>
> -->8--
>
>
> Dave Martin (4):
>   x86/resctrl: Squelch whitespace anomalies in resctrl core code
>   x86/resctrl: Prefer alloc(sizeof(*foo)) idiom in rdt_init_fs_context()
>   x86/resctrl: Relax some asm #includes
>   [SQUASHME] x86/resctrl: Move the resctrl filesystem code to
>     /fs/resctrl
>
> James Morse (31):
>   x86/resctrl: Fix allocation of cleanest CLOSID on platforms with no
>     monitors
>   x86/resctrl: Add a helper to avoid reaching into the arch code
>     resource list
>   x86/resctrl: Move ctrlval string parsing policy away from the arch
>     code
>   x86/resctrl: Add helper for setting CPU default properties
>   x86/resctrl: Remove rdtgroup from update_cpu_closid_rmid()
>   x86/resctrl: Export resctrl fs's init function
>   x86/resctrl: Wrap resctrl_arch_find_domain() around rdt_find_domain()
>   x86/resctrl: Move resctrl types to a separate header
>   x86/resctrl: Add a resctrl helper to reset all the resources
>   x86/resctrl: Move monitor init work to a resctrl init call
>   x86/resctrl: Move monitor exit work to a resctrl exit call
>   x86/resctrl: Move max_{name,data}_width into resctrl code
>   x86/resctrl: Stop using the for_each_*_rdt_resource() walkers
>   x86/resctrl: Export the is_mbm_*_enabled() helpers to asm/resctrl.h
>   x86/resctrl: Add resctrl_arch_is_evt_configurable() to abstract BMEC
>   x86/resctrl: Change mon_event_config_{read,write}() to be arch helpers
>   x86/resctrl: Move mbm_cfg_mask to struct rdt_resource
>   x86/resctrl: Allow resctrl_arch_mon_event_config_write() to return an
>     error
>   x86/resctrl: Add resctrl_arch_ prefix to pseudo lock functions
>   x86/resctrl: Allow an architecture to disable pseudo lock
>   x86/resctrl: Make prefetch_disable_bits belong to the arch code
>   x86/resctrl: Make resctrl_arch_pseudo_lock_fn() take a plr
>   x86/resctrl: Move thread_throttle_mode_init() to be managed by resctrl
>   x86/resctrl: Move get_config_index() to a header
>   x86/resctrl: Claim get_domain_from_cpu() for resctrl
>   x86/resctrl: Describe resctrl's bitmap size assumptions
>   x86/resctrl: Rename resctrl_sched_in() to begin with "resctrl_arch_"
>   x86/resctrl: Drop __init/__exit on assorted symbols
>   fs/resctrl: Add boiler plate for external resctrl code
>   x86/resctrl: Move the filesystem bits to headers visible to fs/resctrl
>   x86/resctrl: Move the resctrl filesystem code to /fs/resctrl
>
>  MAINTAINERS                               |    2 +
>  arch/Kconfig                              |    8 +
>  arch/x86/Kconfig                          |    5 +-
>  arch/x86/include/asm/resctrl.h            |   45 +-
>  arch/x86/kernel/cpu/resctrl/Makefile      |    5 +-
>  arch/x86/kernel/cpu/resctrl/core.c        |  119 +-
>  arch/x86/kernel/cpu/resctrl/ctrlmondata.c |  506 +--
>  arch/x86/kernel/cpu/resctrl/internal.h    |  436 +--
>  arch/x86/kernel/cpu/resctrl/monitor.c     |  813 +---
>  arch/x86/kernel/cpu/resctrl/pseudo_lock.c | 1130 +-----
>  arch/x86/kernel/cpu/resctrl/rdtgroup.c    | 4205 +--------------------
>  arch/x86/kernel/process_32.c              |    2 +-
>  arch/x86/kernel/process_64.c              |    2 +-
>  fs/Kconfig                                |    1 +
>  fs/Makefile                               |    1 +
>  fs/resctrl/Kconfig                        |   36 +
>  fs/resctrl/Makefile                       |    3 +
>  fs/resctrl/ctrlmondata.c                  |  527 +++
>  fs/resctrl/internal.h                     |  338 ++
>  fs/resctrl/monitor.c                      |  843 +++++
>  fs/resctrl/pseudo_lock.c                  | 1122 ++++++
>  fs/resctrl/rdtgroup.c                     | 4013 ++++++++++++++++++++
>  include/linux/resctrl.h                   |  157 +-
>  include/linux/resctrl_types.h             |   98 +
>  24 files changed, 7402 insertions(+), 7015 deletions(-)
>  create mode 100644 fs/resctrl/Kconfig
>  create mode 100644 fs/resctrl/Makefile
>  create mode 100644 fs/resctrl/ctrlmondata.c
>  create mode 100644 fs/resctrl/internal.h
>  create mode 100644 fs/resctrl/monitor.c
>  create mode 100644 fs/resctrl/pseudo_lock.c
>  create mode 100644 fs/resctrl/rdtgroup.c
>  create mode 100644 include/linux/resctrl_types.h

I was able to build a kernel with the changes and ran through our
internal suite of functional tests on the following implementations:

- AMD EPYC 7B12 64-Core Processor
- Intel(R) Xeon(R) Platinum 8581C

and the results looked good.

Tested-by: Peter Newman <peternewman@google.com>

Thanks!