Commit 4af4a88e authored by Vikas Shivappa's avatar Vikas Shivappa Committed by Thomas Gleixner
Browse files

x86/intel_rdt/cqm: Add mount,umount support 



Add monitoring support during mount and unmount. Since root directory is
a "ctrl_mon" directory which can control and monitor resources create
the "mon_groups" directory which can hold monitor groups and a
"mon_data" directory which would hold all monitoring data like the rest
of resource groups.

The mount succeeds if either of monitoring or control/allocation is
enabled. If only monitoring is enabled user can still create monitor
groups under the "/sys/fs/resctrl/mon_groups/" and any mkdir under root
would fail. If only control/allocation is enabled all of the monitoring
related directories/files would not exist and resctrl would work in
legacy mode.

Signed-off-by: default avatarVikas Shivappa <vikas.shivappa@linux.intel.com>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Cc: ravi.v.shankar@intel.com
Cc: tony.luck@intel.com
Cc: fenghua.yu@intel.com
Cc: peterz@infradead.org
Cc: eranian@google.com
Cc: vikas.shivappa@intel.com
Cc: ak@linux.intel.com
Cc: davidcc@google.com
Cc: reinette.chatre@intel.com
Link: http://lkml.kernel.org/r/1501017287-28083-23-git-send-email-vikas.shivappa@linux.intel.com
parent f3cbeaca

arch/x86/kernel/cpu/intel_rdt.h

+4 −0
Original line number Diff line number Diff line
@@ -22,6 +22,8 @@ 
#define RMID_VAL_ERROR			BIT_ULL(63)

#define RMID_VAL_UNAVAIL		BIT_ULL(62)



DECLARE_STATIC_KEY_FALSE(rdt_enable_key);



/**

 * struct mon_evt - Entry in the event list of a resource

 * @evtid:		event id
@@ -59,6 +61,8 @@ extern bool rdt_alloc_capable; 
extern bool rdt_mon_capable;

extern unsigned int rdt_mon_features;



DECLARE_STATIC_KEY_FALSE(rdt_mon_enable_key);



enum rdt_group_type {

	RDTCTRL_GROUP = 0,

	RDTMON_GROUP,

arch/x86/kernel/cpu/intel_rdt_monitor.c

+1 −0
Original line number Diff line number Diff line
@@ -343,6 +343,7 @@ void mon_event_count(void *info) 
		}

	}

}



static int dom_data_init(struct rdt_resource *r)

{

	struct rmid_entry *entry = NULL;

arch/x86/kernel/cpu/intel_rdt_rdtgroup.c

+57 −4
Original line number Diff line number Diff line
@@ -35,6 +35,8 @@ 
#include <asm/intel_rdt_sched.h>

#include "intel_rdt.h"



DEFINE_STATIC_KEY_FALSE(rdt_enable_key);

DEFINE_STATIC_KEY_FALSE(rdt_mon_enable_key);

DEFINE_STATIC_KEY_FALSE(rdt_alloc_enable_key);

static struct kernfs_root *rdt_root;

struct rdtgroup rdtgroup_default;
@@ -43,6 +45,12 @@ LIST_HEAD(rdt_all_groups); 
/* Kernel fs node for "info" directory under root */

static struct kernfs_node *kn_info;



/* Kernel fs node for "mon_groups" directory under root */

static struct kernfs_node *kn_mongrp;



/* Kernel fs node for "mon_data" directory under root */

static struct kernfs_node *kn_mondata;



/*

 * Trivial allocator for CLOSIDs. Since h/w only supports a small number,

 * we can keep a bitmap of free CLOSIDs in a single integer.
@@ -1044,6 +1052,10 @@ void rdtgroup_kn_unlock(struct kernfs_node *kn) 
	}

}



static int mkdir_mondata_all(struct kernfs_node *parent_kn,

			     struct rdtgroup *prgrp,

			     struct kernfs_node **mon_data_kn);



static struct dentry *rdt_mount(struct file_system_type *fs_type,

				int flags, const char *unused_dev_name,

				void *data)
@@ -1055,7 +1067,7 @@ static struct dentry *rdt_mount(struct file_system_type *fs_type, 
	/*

	 * resctrl file system can only be mounted once.

	 */

	if (static_branch_unlikely(&rdt_alloc_enable_key)) {

	if (static_branch_unlikely(&rdt_enable_key)) {

		dentry = ERR_PTR(-EBUSY);

		goto out;

	}
@@ -1074,15 +1086,47 @@ static struct dentry *rdt_mount(struct file_system_type *fs_type, 
		goto out_cdp;

	}



	if (rdt_mon_capable) {

		ret = mongroup_create_dir(rdtgroup_default.kn,

					  NULL, "mon_groups",

					  &kn_mongrp);

		if (ret) {

			dentry = ERR_PTR(ret);

			goto out_info;

		}

		kernfs_get(kn_mongrp);



		ret = mkdir_mondata_all(rdtgroup_default.kn,

					&rdtgroup_default, &kn_mondata);

		if (ret) {

			dentry = ERR_PTR(ret);

			goto out_mongrp;

		}

		kernfs_get(kn_mondata);

		rdtgroup_default.mon.mon_data_kn = kn_mondata;

	}



	dentry = kernfs_mount(fs_type, flags, rdt_root,

			      RDTGROUP_SUPER_MAGIC, NULL);

	if (IS_ERR(dentry))

		goto out_destroy;

		goto out_mondata;



	if (rdt_alloc_capable)

		static_branch_enable(&rdt_alloc_enable_key);

	if (rdt_mon_capable)

		static_branch_enable(&rdt_mon_enable_key);



	if (rdt_alloc_capable || rdt_mon_capable)

		static_branch_enable(&rdt_enable_key);

	goto out;



out_destroy:

out_mondata:

	if (rdt_mon_capable)

		kernfs_remove(kn_mondata);

out_mongrp:

	if (rdt_mon_capable)

		kernfs_remove(kn_mongrp);

out_info:

	kernfs_remove(kn_info);

out_cdp:

	cdp_disable();
@@ -1204,6 +1248,9 @@ static void rmdir_all_sub(void) 
	rdt_move_group_tasks(NULL, &rdtgroup_default, NULL);



	list_for_each_entry_safe(rdtgrp, tmp, &rdt_all_groups, rdtgroup_list) {

		/* Free any child rmids */

		free_all_child_rdtgrp(rdtgrp);



		/* Remove each rdtgroup other than root */

		if (rdtgrp == &rdtgroup_default)

			continue;
@@ -1216,6 +1263,8 @@ static void rmdir_all_sub(void) 
		cpumask_or(&rdtgroup_default.cpu_mask,

			   &rdtgroup_default.cpu_mask, &rdtgrp->cpu_mask);



		free_rmid(rdtgrp->mon.rmid);



		kernfs_remove(rdtgrp->kn);

		list_del(&rdtgrp->rdtgroup_list);

		kfree(rdtgrp);
@@ -1226,6 +1275,8 @@ static void rmdir_all_sub(void) 
	put_online_cpus();



	kernfs_remove(kn_info);

	kernfs_remove(kn_mongrp);

	kernfs_remove(kn_mondata);

}



static void rdt_kill_sb(struct super_block *sb)
@@ -1240,6 +1291,8 @@ static void rdt_kill_sb(struct super_block *sb) 
	cdp_disable();

	rmdir_all_sub();

	static_branch_disable(&rdt_alloc_enable_key);

	static_branch_disable(&rdt_mon_enable_key);

	static_branch_disable(&rdt_enable_key);

	kernfs_kill_sb(sb);

	mutex_unlock(&rdtgroup_mutex);

}

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