Commit 16ff6b03 authored by Babu Moger's avatar Babu Moger Committed by Borislav Petkov (AMD)
Browse files

fs/resctrl: Introduce interface to display number of free MBM counters 



Introduce the "available_mbm_cntrs" resctrl file to display the number of
counters available for assignment in each domain when "mbm_event" mode is
enabled.

Signed-off-by: default avatarBabu Moger <babu.moger@amd.com>
Signed-off-by: default avatarBorislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: default avatarReinette Chatre <reinette.chatre@intel.com>
Link: https://lore.kernel.org/cover.1757108044.git.babu.moger@amd.com
parent 4d32c24a

Documentation/filesystems/resctrl.rst

+11 −0
Original line number Diff line number Diff line
@@ -299,6 +299,17 @@ with the following files: 
	  # cat /sys/fs/resctrl/info/L3_MON/num_mbm_cntrs

	  0=32;1=32



"available_mbm_cntrs":

	The number of counters available for assignment in each domain when mbm_event

	mode is enabled on the system.



	For example, on a system with 30 available [hardware] assignable counters

	in each of its L3 domains:

	::



	  # cat /sys/fs/resctrl/info/L3_MON/available_mbm_cntrs

	  0=30;1=30



"max_threshold_occupancy":

		Read/write file provides the largest value (in

		bytes) at which a previously used LLC_occupancy

fs/resctrl/internal.h

+3 −0
Original line number Diff line number Diff line
@@ -388,6 +388,9 @@ int resctrl_mbm_assign_mode_show(struct kernfs_open_file *of, struct seq_file *s 


int resctrl_num_mbm_cntrs_show(struct kernfs_open_file *of, struct seq_file *s, void *v);



int resctrl_available_mbm_cntrs_show(struct kernfs_open_file *of, struct seq_file *s,

				     void *v);



#ifdef CONFIG_RESCTRL_FS_PSEUDO_LOCK

int rdtgroup_locksetup_enter(struct rdtgroup *rdtgrp);

fs/resctrl/monitor.c

+44 −0
Original line number Diff line number Diff line
@@ -936,6 +936,48 @@ int resctrl_num_mbm_cntrs_show(struct kernfs_open_file *of, 
	return 0;

}



int resctrl_available_mbm_cntrs_show(struct kernfs_open_file *of,

				     struct seq_file *s, void *v)

{

	struct rdt_resource *r = rdt_kn_parent_priv(of->kn);

	struct rdt_mon_domain *dom;

	bool sep = false;

	u32 cntrs, i;

	int ret = 0;



	cpus_read_lock();

	mutex_lock(&rdtgroup_mutex);



	rdt_last_cmd_clear();



	if (!resctrl_arch_mbm_cntr_assign_enabled(r)) {

		rdt_last_cmd_puts("mbm_event counter assignment mode is not enabled\n");

		ret = -EINVAL;

		goto out_unlock;

	}



	list_for_each_entry(dom, &r->mon_domains, hdr.list) {

		if (sep)

			seq_putc(s, ';');



		cntrs = 0;

		for (i = 0; i < r->mon.num_mbm_cntrs; i++) {

			if (!dom->cntr_cfg[i].rdtgrp)

				cntrs++;

		}



		seq_printf(s, "%d=%u", dom->hdr.id, cntrs);

		sep = true;

	}

	seq_putc(s, '\n');



out_unlock:

	mutex_unlock(&rdtgroup_mutex);

	cpus_read_unlock();



	return ret;

}



/**

 * resctrl_mon_resource_init() - Initialise global monitoring structures.

 *
@@ -983,6 +1025,8 @@ int resctrl_mon_resource_init(void) 
			resctrl_enable_mon_event(QOS_L3_MBM_LOCAL_EVENT_ID);

		resctrl_file_fflags_init("num_mbm_cntrs",

					 RFTYPE_MON_INFO | RFTYPE_RES_CACHE);

		resctrl_file_fflags_init("available_mbm_cntrs",

					 RFTYPE_MON_INFO | RFTYPE_RES_CACHE);

	}



	return 0;

fs/resctrl/rdtgroup.c

+6 −0
Original line number Diff line number Diff line
@@ -1822,6 +1822,12 @@ static struct rftype res_common_files[] = { 
		.seq_show	= rdt_mon_features_show,

		.fflags		= RFTYPE_MON_INFO,

	},

	{

		.name		= "available_mbm_cntrs",

		.mode		= 0444,

		.kf_ops		= &rdtgroup_kf_single_ops,

		.seq_show	= resctrl_available_mbm_cntrs_show,

	},

	{

		.name		= "num_rmids",

		.mode		= 0444,