Commit 04b247c2 authored by Sebastian Andrzej Siewior's avatar Sebastian Andrzej Siewior Committed by Thomas Gleixner

perf/x86/intel/cqm: Use cpuhp_setup_state_cpuslocked()

intel_cqm_init() holds get_online_cpus() while registerring the hotplug
callbacks.

cpuhp_setup_state() invokes get_online_cpus() as well. This is correct, but
prevents the conversion of the hotplug locking to a percpu rwsem.

Use cpuhp_setup_state_cpuslocked() to avoid the nested call. Convert
*_online_cpus() to the new interfaces while at it.
Signed-off-by: default avatarSebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Acked-by: default avatarIngo Molnar <mingo@kernel.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170524081548.075604046@linutronix.de
parent e9f5d63f
......@@ -1682,7 +1682,7 @@ static int __init intel_cqm_init(void)
*
* Also, check that the scales match on all cpus.
*/
get_online_cpus();
cpus_read_lock();
for_each_online_cpu(cpu) {
struct cpuinfo_x86 *c = &cpu_data(cpu);
......@@ -1746,14 +1746,14 @@ static int __init intel_cqm_init(void)
* Setup the hot cpu notifier once we are sure cqm
* is enabled to avoid notifier leak.
*/
cpuhp_setup_state(CPUHP_AP_PERF_X86_CQM_STARTING,
cpuhp_setup_state_cpuslocked(CPUHP_AP_PERF_X86_CQM_STARTING,
"perf/x86/cqm:starting",
intel_cqm_cpu_starting, NULL);
cpuhp_setup_state(CPUHP_AP_PERF_X86_CQM_ONLINE, "perf/x86/cqm:online",
cpuhp_setup_state_cpuslocked(CPUHP_AP_PERF_X86_CQM_ONLINE,
"perf/x86/cqm:online",
NULL, intel_cqm_cpu_exit);
out:
put_online_cpus();
cpus_read_unlock();
if (ret) {
kfree(str);
......
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