Commit-ID: 04b247c2ebdd6ba1c46c7c22546229a89760b43a
Gitweb: http://git.kernel.org/tip/04b247c2ebdd6ba1c46c7c22546229a89760b43a
Author: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
AuthorDate: Wed, 24 May 2017 10:15:24 +0200
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Fri, 26 May 2017 10:10:40 +0200
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: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Acked-by: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
Cc: Fenghua Yu <fenghua.yu@xxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Link: http://lkml.kernel.org/r/20170524081548.075604046@xxxxxxxxxxxxx
---
arch/x86/events/intel/cqm.c | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)
diff --git a/arch/x86/events/intel/cqm.c b/arch/x86/events/intel/cqm.c
index 8c00dc0..2521f77 100644
--- a/arch/x86/events/intel/cqm.c
+++ b/arch/x86/events/intel/cqm.c
@@ -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,
- "perf/x86/cqm:starting",
- intel_cqm_cpu_starting, NULL);
- cpuhp_setup_state(CPUHP_AP_PERF_X86_CQM_ONLINE, "perf/x86/cqm:online",
- NULL, intel_cqm_cpu_exit);
-
+ cpuhp_setup_state_cpuslocked(CPUHP_AP_PERF_X86_CQM_STARTING,
+ "perf/x86/cqm:starting",
+ intel_cqm_cpu_starting, NULL);
+ 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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