Re: [PATCH v14 20/32] x86/resctrl: Read telemetry events

Reinette Chatre
2025-12-02T16:21:41Z

Hi Tony,

On 11/24/25 10:53 AM, Tony Luck wrote:
> Introduce intel_aet_read_event() to read telemetry events for resource
> RDT_RESOURCE_PERF_PKG. There may be multiple aggregators tracking each package,
> so scan all of them and add up all counters. Aggregators may return an invalid
> data indication if they have received no records for a given RMID. User will
> see "Unavailable" if none of the aggregators on a package provide valid counts.
>
> Resctrl now uses readq() so depends on X86_64. Update Kconfig.
>
> Signed-off-by: Tony Luck <tony.luck@intel.com>
> ---

...

> diff --git a/arch/x86/kernel/cpu/resctrl/intel_aet.c b/arch/x86/kernel/cpu/resctrl/intel_aet.c
> index b6b50650e634..bf3c70590d4c 100644
> --- a/arch/x86/kernel/cpu/resctrl/intel_aet.c
> +++ b/arch/x86/kernel/cpu/resctrl/intel_aet.c
> @@ -12,13 +12,17 @@
> #define pr_fmt(fmt) "resctrl: " fmt
>
> #include <linux/array_size.h>
> +#include <linux/bits.h>
> #include <linux/cleanup.h>
> #include <linux/compiler_types.h>
> +#include <linux/container_of.h>
> #include <linux/cpu.h>
> #include <linux/err.h>
> +#include <linux/errno.h>
> #include <linux/init.h>
> #include <linux/intel_pmt_features.h>
> #include <linux/intel_vsec.h>
> +#include <linux/io.h>
> #include <linux/overflow.h>
> #include <linux/printk.h>
> #include <linux/resctrl.h>
> @@ -221,3 +225,50 @@ void __exit intel_aet_exit(void)
> }
> }
> }
> +
> +#define DATA_VALID BIT_ULL(63)
> +#define DATA_BITS GENMASK_ULL(62, 0)
> +
> +/*
> + * Read counter for an event on a domain (summing all aggregators
> + * on the domain). If an aggregator hasn't received any data for a
> + * specific RMID, the MMIO read indicates that data is not valid.
> + * Return success if at least one aggregator has valid data.

unnecessary short lines

> + */
> +int intel_aet_read_event(int domid, u32 rmid, void *arch_priv, u64 *val)
> +{

| Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>

Reinette