Hi Babu,
On 12/12/24 12:15 PM, Babu Moger wrote:
> The mbm_cntr_assign mode provides an option to the user to assign a
> counter to an RMID, event pair and monitor the bandwidth as long as
> the counter is assigned. Number of assignments depend on number of
> monitoring counters available.
>
> Provide the interface to display the number of monitoring counters
> supported. The interface file 'num_mbm_cntrs' is available when an
> architecture supports mbm_cntr_assign mode.
How about: "The resctrl file 'num_mbm_cntrs' is visible to user space
when the system supports mbm_cntr_assign mode." ?
>
> Signed-off-by: Babu Moger <babu.moger@xxxxxxx>
> ---
> v10: No changes.
>
> v9: Updated user document based on the comments.
> Will add a new file available_mbm_cntrs later in the series.
>
> v8: Commit message update and documentation update.
>
> v7: Minor commit log text changes.
>
> v6: No changes.
>
> v5: Changed the display name from num_cntrs to num_mbm_cntrs.
> Updated the commit message.
> Moved the patch after mbm_mode is introduced.
>
> v4: Changed the counter name to num_cntrs. And few text changes.
>
> v3: Changed the field name to mbm_assign_cntrs.
>
> v2: Changed the field name to mbm_assignable_counters from abmc_counter.
> ---
> ---
> Documentation/arch/x86/resctrl.rst | 12 ++++++++++++
> arch/x86/kernel/cpu/resctrl/monitor.c | 1 +
> arch/x86/kernel/cpu/resctrl/rdtgroup.c | 16 ++++++++++++++++
> 3 files changed, 29 insertions(+)
>
> diff --git a/Documentation/arch/x86/resctrl.rst b/Documentation/arch/x86/resctrl.rst
> index 1e4a1f615496..43a861adeada 100644
> --- a/Documentation/arch/x86/resctrl.rst
> +++ b/Documentation/arch/x86/resctrl.rst
> @@ -290,6 +290,18 @@ with the following files:
> "mbm_total_bytes" or "mbm_local_bytes" will report 'Unavailable' if
> there is no counter associated with that event.
>
> +"num_mbm_cntrs":
> + The number of monitoring counters available for assignment when the
> + architecture supports mbm_cntr_assign mode.
"architecture supports" -> "system supports"
> +
> + The resctrl file system supports tracking up to two memory bandwidth
> + events per monitoring group: mbm_total_bytes and/or mbm_local_bytes.
> + Up to two counters can be assigned per monitoring group, one for each
> + memory bandwidth event. More monitoring groups can be tracked by
> + assigning one counter per monitoring group. However, doing so limits
> + memory bandwidth tracking to a single memory bandwidth event per
> + monitoring group.
> +
> "max_threshold_occupancy":
> Read/write file provides the largest value (in
> bytes) at which a previously used LLC_occupancy
> diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c
> index 80be91671dc1..c23e94fa6852 100644
> --- a/arch/x86/kernel/cpu/resctrl/monitor.c
> +++ b/arch/x86/kernel/cpu/resctrl/monitor.c
> @@ -1237,6 +1237,7 @@ int __init rdt_get_mon_l3_config(struct rdt_resource *r)
> r->mon.mbm_cntr_assignable = true;
> cpuid_count(0x80000020, 5, &eax, &ebx, &ecx, &edx);
> r->mon.num_mbm_cntrs = (ebx & GENMASK(15, 0)) + 1;
> + resctrl_file_fflags_init("num_mbm_cntrs", RFTYPE_MON_INFO);
> }
> }
>
> diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> index f25ff1430014..339bb0b09a82 100644
> --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> @@ -869,6 +869,16 @@ static int rdtgroup_mbm_assign_mode_show(struct kernfs_open_file *of,
> return 0;
> }
>
> +static int rdtgroup_num_mbm_cntrs_show(struct kernfs_open_file *of,
> + struct seq_file *s, void *v)
No rdtgroup_ namespace, this can be resctrl_
> +{
> + struct rdt_resource *r = of->kn->parent->priv;
> +
> + seq_printf(s, "%d\n", r->mon.num_mbm_cntrs);
> +
> + return 0;
> +}
> +
> #ifdef CONFIG_PROC_CPU_RESCTRL
>
> /*
Reinette
