Commit b4005e92 authored by Thomas Gleixner's avatar Thomas Gleixner Committed by Rafael J. Wysocki
Browse files

powercap/intel_rapl: Track active CPUs internally 



The ability of the CPU hotplug code to stop online/offline at each step
makes it necessary to track the activated CPUs in a package directly,
because outerwise a CPU offline callback can find CPUs which have already
executed the offline callback, but are not yet marked offline in the
topology mask. That could make such a CPU the package leader and in case
that CPU goes fully offline leave the package lead orphaned.

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Tested-by: default avatarJacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent 58705069

drivers/powercap/intel_rapl.c

+24 −35
Original line number Diff line number Diff line
@@ -189,14 +189,13 @@ struct rapl_package { 
	unsigned int time_unit;

	struct rapl_domain *domains; /* array of domains, sized at runtime */

	struct powercap_zone *power_zone; /* keep track of parent zone */

	int nr_cpus; /* active cpus on the package, topology info is lost during

		      * cpu hotplug. so we have to track ourselves.

		      */

	unsigned long power_limit_irq; /* keep track of package power limit

					* notify interrupt enable status.

					*/

	struct list_head plist;

	int lead_cpu; /* one active cpu per package for access */

	/* Track active cpus */

	struct cpumask cpumask;

};



struct rapl_defaults {
@@ -1432,19 +1431,17 @@ static void rapl_remove_package(struct rapl_package *rp) 
}



/* called from CPU hotplug notifier, hotplug lock held */

static int rapl_add_package(int cpu)

static struct rapl_package *rapl_add_package(int cpu, int pkgid)

{

	struct rapl_package *rp;

	int ret, phy_package_id;

	int ret;



	phy_package_id = topology_physical_package_id(cpu);

	rp = kzalloc(sizeof(struct rapl_package), GFP_KERNEL);

	if (!rp)

		return -ENOMEM;

		return ERR_PTR(-ENOMEM);



	/* add the new package to the list */

	rp->id = phy_package_id;

	rp->nr_cpus = 1;

	rp->id = pkgid;

	rp->lead_cpu = cpu;



	/* check if the package contains valid domains */
@@ -1457,14 +1454,13 @@ static int rapl_add_package(int cpu) 
	if (!ret) {

		INIT_LIST_HEAD(&rp->plist);

		list_add(&rp->plist, &rapl_packages);

		return 0;

		return rp;

	}



err_free_package:

	kfree(rp->domains);

	kfree(rp);



	return ret;

	return ERR_PTR(ret);

}



/* Handles CPU hotplug on multi-socket systems.
@@ -1476,42 +1472,35 @@ err_free_package: 
 */

static int rapl_cpu_online(unsigned int cpu)

{

	int pkgid = topology_physical_package_id(cpu);

	struct rapl_package *rp;

	int phy_package_id;



	phy_package_id = topology_physical_package_id(cpu);



	rp = find_package_by_id(phy_package_id);

	if (rp) {

		rp->nr_cpus++;

		return 0;

	rp = find_package_by_id(pkgid);

	if (!rp) {

		rp = rapl_add_package(cpu, pkgid);

		if (IS_ERR(rp))

			return PTR_ERR(rp);

	}

	return rapl_add_package(cpu);

	cpumask_set_cpu(cpu, &rp->cpumask);

	return 0;

}



static int rapl_cpu_down_prep(unsigned int cpu)

{

	int phy_package_id;

	int pkgid = topology_physical_package_id(cpu);

	struct rapl_package *rp;

	int lead_cpu;



	phy_package_id = topology_physical_package_id(cpu);

	rp = find_package_by_id(phy_package_id);

	rp = find_package_by_id(pkgid);

	if (!rp)

		return 0;

	if (--rp->nr_cpus == 0) {



	cpumask_clear_cpu(cpu, &rp->cpumask);

	lead_cpu = cpumask_first(&rp->cpumask);

	if (lead_cpu >= nr_cpu_ids)

		rapl_remove_package(rp);

	} else if (cpu == rp->lead_cpu) {

		/* choose another active cpu in the package */

		lead_cpu = cpumask_any_but(topology_core_cpumask(cpu), cpu);

		if (lead_cpu < nr_cpu_ids) {

	else if (rp->lead_cpu == cpu)

		rp->lead_cpu = lead_cpu;

		} else {

			/* should never go here */

			pr_err("no active cpu available for package %d\n",

			       phy_package_id);

		}

	}

	return 0;

}

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