Re: [PATCH v8 24/25] x86/resctrl: Introduce interface to list assignment states of all the groups

[Reinette Chatre]

Hi Babu,

On 10/9/24 10:39 AM, Babu Moger wrote:
> Provide the interface to list the assignment states of all the resctrl
> groups in mbm_cntr_assign mode.
> 
> Example:
> $mount -t resctrl resctrl /sys/fs/resctrl/
> $cat /sys/fs/resctrl/info/L3_MON/mbm_assign_control
> //0=tl;1=tl;
> 
> List follows the following format:
> 
> "<CTRL_MON group>/<MON group>/<domain_id>=<flags>"
> 
> Format for specific type of groups:
> 
> - Default CTRL_MON group:
>   "//<domain_id>=<flags>"
> 
> - Non-default CTRL_MON group:
>   "<CTRL_MON group>//<domain_id>=<flags>"
> 
> - Child MON group of default CTRL_MON group:
>   "/<MON group>/<domain_id>=<flags>"
> 
> - Child MON group of non-default CTRL_MON group:
>   "<CTRL_MON group>/<MON group>/<domain_id>=<flags>"
> 
> Flags can be one of the following:
> t  MBM total event is enabled
> l  MBM local event is enabled
> tl Both total and local MBM events are enabled
> _  None of the MBM events are enabled
> 
> Signed-off-by: Babu Moger <babu.moger@xxxxxxx>
> ---
> v8: Moved resctrl_mbm_event_assigned() in here as it is first used here.
>     Moved rdt_last_cmd_clear() before making any call.
>     Updated the commit log.
>     Corrected the doc format.
> 
> v7: Renamed the interface name from 'mbm_control' to 'mbm_assign_control'
>     to match 'mbm_assign_mode'.
>     Removed Arch references from FS code.
>     Added rdt_last_cmd_clear() before the command processing.
>     Added rdtgroup_mutex before all the calls.
>     Removed references of ABMC from FS code.
> 
> v6: The domain specific assignment can be determined looking at mbm_cntr_map.
>     Removed rdtgroup_abmc_dom_cfg() and rdtgroup_abmc_dom_state().
>     Removed the switch statement for the domain_state detection.
>     Determined the flags incremently.
>     Removed special handling of default group while printing..
> 
> v5: Replaced "assignment flags" with "flags".
>     Changes related to mon structure.
>     Changes related renaming the interface from mbm_assign_control to
>     mbm_control.
> 
> v4: Added functionality to query domain specific assigment in.
>     rdtgroup_abmc_dom_state().
> 
> v3: New patch.
>     Addresses the feedback to provide the global assignment interface.
>     https://lore.kernel.org/lkml/c73f444b-83a1-4e9a-95d3-54c5165ee782@xxxxxxxxx/
> ---
>  Documentation/arch/x86/resctrl.rst     | 44 +++++++++++++++
>  arch/x86/kernel/cpu/resctrl/monitor.c  |  1 +
>  arch/x86/kernel/cpu/resctrl/rdtgroup.c | 76 ++++++++++++++++++++++++++
>  3 files changed, 121 insertions(+)
> 
> diff --git a/Documentation/arch/x86/resctrl.rst b/Documentation/arch/x86/resctrl.rst
> index d9574078f735..b85d3bc3e301 100644
> --- a/Documentation/arch/x86/resctrl.rst
> +++ b/Documentation/arch/x86/resctrl.rst
> @@ -310,6 +310,50 @@ with the following files:
>  	The number of monitoring counters available for assignment when the
>  	architecture supports mbm_cntr_assign mode.
>  
> +"mbm_assign_control":
> +	Reports the resctrl group and monitor status of each group.
> +
> +	List follows the following format:
> +		"<CTRL_MON group>/<MON group>/<domain_id>=<flags>"
> +
> +	Format for specific type of groups:
> +
> +	* Default CTRL_MON group:
> +		"//<domain_id>=<flags>"
> +
> +	* Non-default CTRL_MON group:
> +		"<CTRL_MON group>//<domain_id>=<flags>"
> +
> +	* Child MON group of default CTRL_MON group:
> +		"/<MON group>/<domain_id>=<flags>"
> +
> +	* Child MON group of non-default CTRL_MON group:
> +		"<CTRL_MON group>/<MON group>/<domain_id>=<flags>"
> +
> +	Flags can be one of the following:
> +	::
> +
> +	 t  MBM total event is assigned.
> +	 l  MBM local event is assigned.
> +	 tl Both total and local MBM events are assigned.
> +	 _  None of the MBM events are assigned.
> +
> +	Examples:
> +	::
> +
> +	 # mkdir /sys/fs/resctrl/mon_groups/child_default_mon_grp
> +	 # mkdir /sys/fs/resctrl/non_default_ctrl_mon_grp
> +	 # mkdir /sys/fs/resctrl/non_default_ctrl_mon_grp/mon_groups/child_non_default_mon_grp
> +
> +	 # cat /sys/fs/resctrl/info/L3_MON/mbm_assign_control
> +	 non_default_ctrl_mon_grp//0=tl;1=tl;
> +	 non_default_ctrl_mon_grp/child_non_default_mon_grp/0=tl;1=tl;
> +	 //0=tl;1=tl;
> +	 /child_default_mon_grp/0=tl;1=tl;
> +
> +	There are four resctrl groups. All the groups have total and local MBM events
> +	assigned on domain 0 and 1.
> +
>  "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 395d99984893..fa7c77935080 100644
> --- a/arch/x86/kernel/cpu/resctrl/monitor.c
> +++ b/arch/x86/kernel/cpu/resctrl/monitor.c
> @@ -1269,6 +1269,7 @@ int __init rdt_get_mon_l3_config(struct rdt_resource *r)
>  			r->mon.num_mbm_cntrs = (ebx & GENMASK(15, 0)) + 1;
>  			resctrl_file_fflags_init("num_mbm_cntrs", RFTYPE_MON_INFO);
>  			hw_res->mbm_cntr_assign_enabled = true;
> +			resctrl_file_fflags_init("mbm_assign_control", RFTYPE_MON_INFO);
>  		}
>  	}
>  
> diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> index cf2e0ad0e4f4..cf92ceb0f05e 100644
> --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
> @@ -970,6 +970,76 @@ static int rdtgroup_num_mbm_cntrs_show(struct kernfs_open_file *of,
>  	return 0;
>  }
>  
> +static bool resctrl_mbm_event_assigned(struct rdtgroup *rdtg,
> +				       struct rdt_mon_domain *d, u32 evtid)

u32 -> enum resctrl_event_id ?

> +{
> +	int index = MBM_EVENT_ARRAY_INDEX(evtid);
> +	int cntr_id = rdtg->mon.cntr_id[index];
> +
> +	return cntr_id != MON_CNTR_UNSET && test_bit(cntr_id, d->mbm_cntr_map);
> +}
> +
> +static char *rdtgroup_mon_state_to_str(struct rdtgroup *rdtgrp,
> +				       struct rdt_mon_domain *d, char *str)
> +{
> +	char *tmp = str;
> +
> +	/* Query the total and local event flags for the domain */
> +	if (resctrl_mbm_event_assigned(rdtgrp, d, QOS_L3_MBM_TOTAL_EVENT_ID))
> +		*tmp++ = 't';
> +
> +	if (resctrl_mbm_event_assigned(rdtgrp, d, QOS_L3_MBM_LOCAL_EVENT_ID))
> +		*tmp++ = 'l';
> +
> +	if (tmp == str)
> +		*tmp++ = '_';
> +
> +	*tmp = '\0';
> +	return str;
> +}
> +

Reinette