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Commit f0704827 authored by Richard Cochran's avatar Richard Cochran Committed by Ingo Molnar
Browse files

perf/x86/intel/cqm: Convert Intel CQM to hotplug state machine 



Install the callbacks via the state machine and let the core invoke
the callbacks on the already online CPUs.

Signed-off-by: default avatarRichard Cochran <rcochran@linutronix.de>
Signed-off-by: default avatarAnna-Maria Gleixner <anna-maria@linutronix.de>
Reviewed-by: default avatarSebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt.fleming@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vikas Shivappa <vikas.shivappa@linux.intel.com>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160713153334.096956222@linutronix.de


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 8b5b773d

arch/x86/events/intel/cqm.c

+18 −31
Original line number Diff line number Diff line
@@ -1577,7 +1577,7 @@ static inline void cqm_pick_event_reader(int cpu) 
		cpumask_set_cpu(cpu, &cqm_cpumask);

}



static void intel_cqm_cpu_starting(unsigned int cpu)

static int intel_cqm_cpu_starting(unsigned int cpu)

{

	struct intel_pqr_state *state = &per_cpu(pqr_state, cpu);

	struct cpuinfo_x86 *c = &cpu_data(cpu);
@@ -1588,39 +1588,26 @@ static void intel_cqm_cpu_starting(unsigned int cpu) 


	WARN_ON(c->x86_cache_max_rmid != cqm_max_rmid);

	WARN_ON(c->x86_cache_occ_scale != cqm_l3_scale);



	cqm_pick_event_reader(cpu);

	return 0;

}



static void intel_cqm_cpu_exit(unsigned int cpu)

static int intel_cqm_cpu_exit(unsigned int cpu)

{

	int target;



	/* Is @cpu the current cqm reader for this package ? */

	if (!cpumask_test_and_clear_cpu(cpu, &cqm_cpumask))

		return;

		return 0;



	/* Find another online reader in this package */

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



	if (target < nr_cpu_ids)

		cpumask_set_cpu(target, &cqm_cpumask);

}



static int intel_cqm_cpu_notifier(struct notifier_block *nb,

				  unsigned long action, void *hcpu)

{

	unsigned int cpu  = (unsigned long)hcpu;



	switch (action & ~CPU_TASKS_FROZEN) {

	case CPU_DOWN_PREPARE:

		intel_cqm_cpu_exit(cpu);

		break;

	case CPU_STARTING:

		intel_cqm_cpu_starting(cpu);

		cqm_pick_event_reader(cpu);

		break;

	}



	return NOTIFY_OK;

	return 0;

}



static const struct x86_cpu_id intel_cqm_match[] = {
@@ -1682,7 +1669,7 @@ static int intel_mbm_init(void) 
static int __init intel_cqm_init(void)

{

	char *str = NULL, scale[20];

	int i, cpu, ret;

	int cpu, ret;



	if (x86_match_cpu(intel_cqm_match))

		cqm_enabled = true;
@@ -1705,8 +1692,7 @@ static int __init intel_cqm_init(void) 
	 *

	 * Also, check that the scales match on all cpus.

	 */

	cpu_notifier_register_begin();



	get_online_cpus();

	for_each_online_cpu(cpu) {

		struct cpuinfo_x86 *c = &cpu_data(cpu);
@@ -1743,11 +1729,6 @@ static int __init intel_cqm_init(void) 
	if (ret)

		goto out;



	for_each_online_cpu(i) {

		intel_cqm_cpu_starting(i);

		cqm_pick_event_reader(i);

	}



	if (mbm_enabled)

		ret = intel_mbm_init();

	if (ret && !cqm_enabled)
@@ -1772,12 +1753,18 @@ static int __init intel_cqm_init(void) 
		pr_info("Intel MBM enabled\n");



	/*

	 * Register the hot cpu notifier once we are sure cqm

	 * Setup the hot cpu notifier once we are sure cqm

	 * is enabled to avoid notifier leak.

	 */

	__perf_cpu_notifier(intel_cqm_cpu_notifier);

	cpuhp_setup_state(CPUHP_AP_PERF_X86_CQM_STARTING,

			  "AP_PERF_X86_CQM_STARTING",

			  intel_cqm_cpu_starting, NULL);

	cpuhp_setup_state(CPUHP_AP_PERF_X86_CQM_ONLINE, "AP_PERF_X86_CQM_ONLINE",

			  NULL, intel_cqm_cpu_exit);



out:

	cpu_notifier_register_done();

	put_online_cpus();



	if (ret) {

		kfree(str);

		cqm_cleanup();

include/linux/cpuhotplug.h

+2 −0
Original line number Diff line number Diff line
@@ -25,6 +25,7 @@ enum cpuhp_state { 
	CPUHP_AP_PERF_X86_AMD_UNCORE_STARTING,

	CPUHP_AP_PERF_X86_STARTING,

	CPUHP_AP_PERF_X86_AMD_IBS_STARTING,

	CPUHP_AP_PERF_X86_CQM_STARTING,

	CPUHP_AP_NOTIFY_STARTING,

	CPUHP_AP_ONLINE,

	CPUHP_TEARDOWN_CPU,
@@ -36,6 +37,7 @@ enum cpuhp_state { 
	CPUHP_AP_PERF_X86_UNCORE_ONLINE,

	CPUHP_AP_PERF_X86_AMD_UNCORE_ONLINE,

	CPUHP_AP_PERF_X86_RAPL_ONLINE,

	CPUHP_AP_PERF_X86_CQM_ONLINE,

	CPUHP_AP_NOTIFY_ONLINE,

	CPUHP_AP_ONLINE_DYN,

	CPUHP_AP_ONLINE_DYN_END		= CPUHP_AP_ONLINE_DYN + 30,