Re: [PATCH v7 40/49] fs/resctrl: Add boiler plate for external resctrl code

Fenghua Yu
2025-03-07T02:16:34Z

On 2/28/25 11:59, James Morse wrote:
> Add Makefile and Kconfig for fs/resctrl. Add ARCH_HAS_CPU_RESCTRL
> for the common parts of the resctrl interface and make X86_CPU_RESCTRL
> select this.
>
> Adding an include of asm/resctrl.h to linux/resctrl.h allows the
> /fs/resctrl files to switch over to using this header instead.
>
> Co-developed-by: Dave Martin <Dave.Martin@arm.com>
> Signed-off-by: Dave Martin <Dave.Martin@arm.com>
> Signed-off-by: James Morse <james.morse@arm.com>
> Tested-by: Carl Worth <carl@os.amperecomputing.com> # arm64
> Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>
> Reviewed-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>
> Reviewed-by: Tony Luck <tony.luck@intel.com>
> ---
> Changes since v6:
> * Added 'depends on RESCTRL_FS' to the hidden kconfig options.
>
> Changes since v5:
> * Removed double include.
> * Removed duplicate pseudo lock Kconfig define
> * Grammar fix and closid capitalisation change.
>
> Changes since v4:
> * Tweaking of the commit message.
>
> Changes since v3:
> * Reworded 'if unsure say N' from the Kconfig text, the user doesn't have
> the choice anyway at this point.
> * Added PWD to monitor.o's CFLAGS for the ftrace rube-goldberg build machine.
> * Added split trace files.
>
> Changes since v2:
> * Dropped KERNFS dependency from arch side Kconfig.
> * Added empty trace.h file.
> * Merged asm->linux includes from Dave's patch to decouple those
> patches from this series.
>
> Changes since v1:
> * Rename new file psuedo_lock.c to pseudo_lock.c, to match the name
> of the original file (and to be less surprising).
>
> * [Whitespace only] Under RESCTRL_FS in fs/resctrl/Kconfig, delete
> alignment space in orphaned select ... if (which has nothing to line
> up with any more).
>
> * [Whitespace only] Reflow and re-tab Kconfig additions.
> ---
> MAINTAINERS | 1 +
> arch/Kconfig | 8 +++++
> arch/x86/Kconfig | 11 ++-----
> arch/x86/kernel/cpu/resctrl/internal.h | 2 --
> arch/x86/kernel/cpu/resctrl/monitor.c | 2 +-
> arch/x86/kernel/cpu/resctrl/pseudo_lock.c | 2 +-
> arch/x86/kernel/cpu/resctrl/rdtgroup.c | 2 +-
> fs/Kconfig | 1 +
> fs/Makefile | 1 +
> fs/resctrl/Kconfig | 39 +++++++++++++++++++++++
> fs/resctrl/Makefile | 6 ++++
> fs/resctrl/ctrlmondata.c | 0
> fs/resctrl/internal.h | 0
> fs/resctrl/monitor.c | 0
> fs/resctrl/monitor_trace.h | 0
> fs/resctrl/pseudo_lock.c | 0
> fs/resctrl/pseudo_lock_trace.h | 0
> fs/resctrl/rdtgroup.c | 0
> include/linux/resctrl.h | 4 +++
> 19 files changed, 66 insertions(+), 13 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/monitor_trace.h
> create mode 100644 fs/resctrl/pseudo_lock.c
> create mode 100644 fs/resctrl/pseudo_lock_trace.h
> create mode 100644 fs/resctrl/rdtgroup.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 3487ac429a9a..433ba4a5a84a 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -19881,6 +19881,7 @@ S: Supported
> F: Documentation/arch/x86/resctrl*
> F: arch/x86/include/asm/resctrl.h
> F: arch/x86/kernel/cpu/resctrl/
> +F: fs/resctrl/
> F: include/linux/resctrl*.h
> F: tools/testing/selftests/resctrl/
>
> diff --git a/arch/Kconfig b/arch/Kconfig
> index b8a4ff365582..2778a7859c11 100644
> --- a/arch/Kconfig
> +++ b/arch/Kconfig
> @@ -1518,6 +1518,14 @@ config STRICT_MODULE_RWX
> config ARCH_HAS_PHYS_TO_DMA
> bool
>
> +config ARCH_HAS_CPU_RESCTRL
> + bool
> + help
> + An architecture selects this option to indicate that the necessary
> + hooks are provided to support the common memory system usage
> + monitoring and control interfaces provided by the 'resctrl'
> + filesystem (see RESCTRL_FS).
> +
> config HAVE_ARCH_COMPILER_H
> bool
> help
> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> index 1a89574a58f7..ea29d22a621f 100644
> --- a/arch/x86/Kconfig
> +++ b/arch/x86/Kconfig
> @@ -503,8 +503,9 @@ config X86_MPPARSE
> config X86_CPU_RESCTRL
> bool "x86 CPU resource control support"
> depends on X86 && (CPU_SUP_INTEL || CPU_SUP_AMD)
> - select KERNFS
> - select PROC_CPU_RESCTRL if PROC_FS
> + depends on MISC_FILESYSTEMS
> + select ARCH_HAS_CPU_RESCTRL
> + select RESCTRL_FS
> select RESCTRL_FS_PSEUDO_LOCK
> help
> Enable x86 CPU resource control support.
> @@ -522,12 +523,6 @@ config X86_CPU_RESCTRL
>
> Say N if unsure.
>
> -config RESCTRL_FS_PSEUDO_LOCK
> - bool
> - help
> - Software mechanism to pin data in a cache portion using
> - micro-architecture specific knowledge.
> -
> config X86_FRED
> bool "Flexible Return and Event Delivery"
> depends on X86_64
> diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h
> index 16c1a391d012..ee50b7375717 100644
> --- a/arch/x86/kernel/cpu/resctrl/internal.h
> +++ b/arch/x86/kernel/cpu/resctrl/internal.h
> @@ -9,8 +9,6 @@
> #include <linux/jump_label.h>
> #include <linux/tick.h>
>
> -#include <asm/resctrl.h>
> -
> #define L3_QOS_CDP_ENABLE 0x01ULL
>
> #define L2_QOS_CDP_ENABLE 0x01ULL
> diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c
> index 90e7f8754b91..fcd3c41db554 100644
> --- a/arch/x86/kernel/cpu/resctrl/monitor.c
> +++ b/arch/x86/kernel/cpu/resctrl/monitor.c
> @@ -19,11 +19,11 @@
>
> #include <linux/cpu.h>
> #include <linux/module.h>
> +#include <linux/resctrl.h>
> #include <linux/sizes.h>
> #include <linux/slab.h>
>
> #include <asm/cpu_device_id.h>
> -#include <asm/resctrl.h>
>
> #include "internal.h"
>
> diff --git a/arch/x86/kernel/cpu/resctrl/pseudo_lock.c b/arch/x86/kernel/cpu/resctrl/pseudo_lock.c
> index 5c14f4999d55..69dff2bb2c09 100644
> --- a/arch/x86/kernel/cpu/resctrl/pseudo_lock.c
> +++ b/arch/x86/kernel/cpu/resctrl/pseudo_lock.c
> @@ -18,12 +18,12 @@
> #include <linux/mman.h>
> #include <linux/perf_event.h>
> #include <linux/pm_qos.h>
> +#include <linux/resctrl.h>
> #include <linux/slab.h>
> #include <linux/uaccess.h>
>
> #include <asm/cacheflush.h>
> #include <asm/cpu_device_id.h>
> -#include <asm/resctrl.h>
> #include <asm/perf_event.h>
>
> #include "../../events/perf_event.h" /* For X86_CONFIG() */
> diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> index 4209d78b7aae..4108c0de298c 100644
> --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> @@ -18,6 +18,7 @@
> #include <linux/fs_parser.h>
> #include <linux/sysfs.h>
> #include <linux/kernfs.h>
> +#include <linux/resctrl.h>
> #include <linux/seq_buf.h>
> #include <linux/seq_file.h>
> #include <linux/sched/signal.h>
> @@ -28,7 +29,6 @@
>
> #include <uapi/linux/magic.h>
>
> -#include <asm/resctrl.h>
> #include "internal.h"
>
> DEFINE_STATIC_KEY_FALSE(rdt_enable_key);
> diff --git a/fs/Kconfig b/fs/Kconfig
> index 64d420e3c475..709e4d6656e2 100644
> --- a/fs/Kconfig
> +++ b/fs/Kconfig
> @@ -334,6 +334,7 @@ source "fs/omfs/Kconfig"
> source "fs/hpfs/Kconfig"
> source "fs/qnx4/Kconfig"
> source "fs/qnx6/Kconfig"
> +source "fs/resctrl/Kconfig"
> source "fs/romfs/Kconfig"
> source "fs/pstore/Kconfig"
> source "fs/sysv/Kconfig"
> diff --git a/fs/Makefile b/fs/Makefile
> index 15df0a923d3a..73512f13e969 100644
> --- a/fs/Makefile
> +++ b/fs/Makefile
> @@ -129,3 +129,4 @@ obj-$(CONFIG_EROFS_FS) += erofs/
> obj-$(CONFIG_VBOXSF_FS) += vboxsf/
> obj-$(CONFIG_ZONEFS_FS) += zonefs/
> obj-$(CONFIG_BPF_LSM) += bpf_fs_kfuncs.o
> +obj-$(CONFIG_RESCTRL_FS) += resctrl/
> diff --git a/fs/resctrl/Kconfig b/fs/resctrl/Kconfig
> new file mode 100644
> index 000000000000..478a8e2ad99f
> --- /dev/null
> +++ b/fs/resctrl/Kconfig
> @@ -0,0 +1,39 @@
> +config RESCTRL_FS
> + bool "CPU Resource Control Filesystem (resctrl)"
> + depends on ARCH_HAS_CPU_RESCTRL
> + select KERNFS
> + select PROC_CPU_RESCTRL if PROC_FS
> + help
> + Some architectures provide hardware facilities to group tasks and
> + monitor and control their usage of memory system resources such as
> + caches and memory bandwidth. Examples of such facilities include
> + Intel's Resource Director Technology (Intel(R) RDT) and AMD's
> + Platform Quality of Service (AMD QoS).
> +
> + If your system has the necessary support and you want to be able to
> + assign tasks to groups and manipulate the associated resource
> + monitors and controls from userspace, say Y here to get a mountable
> + 'resctrl' filesystem that lets you do just that.
> +
> + If nothing mounts or prods the 'resctrl' filesystem, resource
> + controls and monitors are left in a quiescent, permissive state.
> +
> + On architectures where this can be disabled independently, it is
> + safe to say N.
> +
> + See <file:Documentation/arch/x86/resctrl.rst> for more information.
> +
> +config RESCTRL_FS_PSEUDO_LOCK
> + bool
> + depends on RESCTRL_FS
> + help
> + Software mechanism to pin data in a cache portion using
> + micro-architecture specific knowledge.
> +
> +config RESCTRL_RMID_DEPENDS_ON_CLOSID
> + bool
> + depends on RESCTRL_FS
> + help
> + Enabled by the architecture when the RMID values depend on the CLOSID.
> + This causes the CLOSID allocator to search for CLOSID with clean
> + RMID.
> diff --git a/fs/resctrl/Makefile b/fs/resctrl/Makefile
> new file mode 100644
> index 000000000000..e67f34d2236a
> --- /dev/null
> +++ b/fs/resctrl/Makefile
> @@ -0,0 +1,6 @@
> +# SPDX-License-Identifier: GPL-2.0
> +obj-$(CONFIG_RESCTRL_FS) += rdtgroup.o ctrlmondata.o monitor.o
> +obj-$(CONFIG_RESCTRL_FS_PSEUDO_LOCK) += pseudo_lock.o
> +
> +# To allow define_trace.h's recursive include:
> +CFLAGS_monitor.o = -I$(src)
> diff --git a/fs/resctrl/ctrlmondata.c b/fs/resctrl/ctrlmondata.c
> new file mode 100644
> index 000000000000..e69de29bb2d1
> diff --git a/fs/resctrl/internal.h b/fs/resctrl/internal.h
> new file mode 100644
> index 000000000000..e69de29bb2d1
> diff --git a/fs/resctrl/monitor.c b/fs/resctrl/monitor.c
> new file mode 100644
> index 000000000000..e69de29bb2d1
> diff --git a/fs/resctrl/monitor_trace.h b/fs/resctrl/monitor_trace.h
> new file mode 100644
> index 000000000000..e69de29bb2d1
> diff --git a/fs/resctrl/pseudo_lock.c b/fs/resctrl/pseudo_lock.c
> new file mode 100644
> index 000000000000..e69de29bb2d1
> diff --git a/fs/resctrl/pseudo_lock_trace.h b/fs/resctrl/pseudo_lock_trace.h
> new file mode 100644
> index 000000000000..e69de29bb2d1

If merge patch 45 and 46 together to fix the pseudo_lock_trace.h
compilation fatal issue, it's unnecessary to create pseudo_lock_trace.h
here (and then the empty pseudo_lock_trace.h file will be deleted later
in merged patch 45).

> diff --git a/fs/resctrl/rdtgroup.c b/fs/resctrl/rdtgroup.c
> new file mode 100644
> index 000000000000..e69de29bb2d1
> diff --git a/include/linux/resctrl.h b/include/linux/resctrl.h
> index b8f8240050b4..5c7c8bf2c47f 100644
> --- a/include/linux/resctrl.h
> +++ b/include/linux/resctrl.h
> @@ -8,6 +8,10 @@
> #include <linux/pid.h>
> #include <linux/resctrl_types.h>
>
> +#ifdef CONFIG_ARCH_HAS_CPU_RESCTRL
> +#include <asm/resctrl.h>
> +#endif
> +
> /* CLOSID, RMID value used by the default control group */
> #define RESCTRL_RESERVED_CLOSID 0
> #define RESCTRL_RESERVED_RMID 0

Other than that,

Reviewed-by: Fenghua Yu <fenghua.yu@intel.com>

Thanks.

-Fenghua