lkml.org 
[lkml]   [2016]   [Jul]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[tip:smp/hotplug] perf/x86/intel/cstate: Convert Intel CSTATE to hotplug state machine
Commit-ID:  77c34ef1c3194bfac65883af75baf7dec9fa0d77
Gitweb: http://git.kernel.org/tip/77c34ef1c3194bfac65883af75baf7dec9fa0d77
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
AuthorDate: Wed, 13 Jul 2016 17:16:18 +0000
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Thu, 14 Jul 2016 09:34:35 +0200

perf/x86/intel/cstate: Convert Intel CSTATE 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: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Anna-Maria Gleixner <anna-maria@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: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: kbuild test robot <fengguang.wu@intel.com>
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160713153334.184061086@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
arch/x86/events/intel/cstate.c | 51 +++++++++++++-----------------------------
include/linux/cpuhotplug.h | 2 ++
2 files changed, 17 insertions(+), 36 deletions(-)

diff --git a/arch/x86/events/intel/cstate.c b/arch/x86/events/intel/cstate.c
index 9ba4e41..d6d7be0 100644
--- a/arch/x86/events/intel/cstate.c
+++ b/arch/x86/events/intel/cstate.c
@@ -365,7 +365,7 @@ static int cstate_pmu_event_add(struct perf_event *event, int mode)
* Check if exiting cpu is the designated reader. If so migrate the
* events when there is a valid target available
*/
-static void cstate_cpu_exit(int cpu)
+static int cstate_cpu_exit(unsigned int cpu)
{
unsigned int target;

@@ -390,9 +390,10 @@ static void cstate_cpu_exit(int cpu)
perf_pmu_migrate_context(&cstate_pkg_pmu, cpu, target);
}
}
+ return 0;
}

-static void cstate_cpu_init(int cpu)
+static int cstate_cpu_init(unsigned int cpu)
{
unsigned int target;

@@ -414,31 +415,10 @@ static void cstate_cpu_init(int cpu)
topology_core_cpumask(cpu));
if (has_cstate_pkg && target >= nr_cpu_ids)
cpumask_set_cpu(cpu, &cstate_pkg_cpu_mask);
-}

-static int cstate_cpu_notifier(struct notifier_block *self,
- unsigned long action, void *hcpu)
-{
- unsigned int cpu = (long)hcpu;
-
- switch (action & ~CPU_TASKS_FROZEN) {
- case CPU_STARTING:
- cstate_cpu_init(cpu);
- break;
- case CPU_DOWN_PREPARE:
- cstate_cpu_exit(cpu);
- break;
- default:
- break;
- }
- return NOTIFY_OK;
+ return 0;
}

-static struct notifier_block cstate_cpu_nb = {
- .notifier_call = cstate_cpu_notifier,
- .priority = CPU_PRI_PERF + 1,
-};
-
static struct pmu cstate_core_pmu = {
.attr_groups = core_attr_groups,
.name = "cstate_core",
@@ -599,18 +579,20 @@ static inline void cstate_cleanup(void)

static int __init cstate_init(void)
{
- int cpu, err;
+ int err;

- cpu_notifier_register_begin();
- for_each_online_cpu(cpu)
- cstate_cpu_init(cpu);
+ cpuhp_setup_state(CPUHP_AP_PERF_X86_CSTATE_STARTING,
+ "AP_PERF_X86_CSTATE_STARTING", cstate_cpu_init,
+ NULL);
+ cpuhp_setup_state(CPUHP_AP_PERF_X86_CSTATE_ONLINE,
+ "AP_PERF_X86_CSTATE_ONLINE", NULL, cstate_cpu_exit);

if (has_cstate_core) {
err = perf_pmu_register(&cstate_core_pmu, cstate_core_pmu.name, -1);
if (err) {
has_cstate_core = false;
pr_info("Failed to register cstate core pmu\n");
- goto out;
+ return err;
}
}

@@ -620,12 +602,10 @@ static int __init cstate_init(void)
has_cstate_pkg = false;
pr_info("Failed to register cstate pkg pmu\n");
cstate_cleanup();
- goto out;
+ return err;
}
}
- __register_cpu_notifier(&cstate_cpu_nb);
-out:
- cpu_notifier_register_done();
+
return err;
}

@@ -651,9 +631,8 @@ module_init(cstate_pmu_init);

static void __exit cstate_pmu_exit(void)
{
- cpu_notifier_register_begin();
- __unregister_cpu_notifier(&cstate_cpu_nb);
+ cpuhp_remove_state_nocalls(CPUHP_AP_PERF_X86_CSTATE_ONLINE);
+ cpuhp_remove_state_nocalls(CPUHP_AP_PERF_X86_CSTATE_STARTING);
cstate_cleanup();
- cpu_notifier_register_done();
}
module_exit(cstate_pmu_exit);
diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
index f9399ee..68f4495 100644
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h
@@ -26,6 +26,7 @@ enum cpuhp_state {
CPUHP_AP_PERF_X86_STARTING,
CPUHP_AP_PERF_X86_AMD_IBS_STARTING,
CPUHP_AP_PERF_X86_CQM_STARTING,
+ CPUHP_AP_PERF_X86_CSTATE_STARTING,
CPUHP_AP_NOTIFY_STARTING,
CPUHP_AP_ONLINE,
CPUHP_TEARDOWN_CPU,
@@ -38,6 +39,7 @@ enum cpuhp_state {
CPUHP_AP_PERF_X86_AMD_UNCORE_ONLINE,
CPUHP_AP_PERF_X86_RAPL_ONLINE,
CPUHP_AP_PERF_X86_CQM_ONLINE,
+ CPUHP_AP_PERF_X86_CSTATE_ONLINE,
CPUHP_AP_NOTIFY_ONLINE,
CPUHP_AP_ONLINE_DYN,
CPUHP_AP_ONLINE_DYN_END = CPUHP_AP_ONLINE_DYN + 30,
\
 
 \ /
  Last update: 2016-07-19 09:41    [W:0.534 / U:1.964 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site