leandrof/linux
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

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

Browse Source 
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@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo 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
This commit is contained in:
Sebastian Andrzej Siewior 2017-05-24 10:15:24 +02:00 committed by Thomas Gleixner
parent e9f5d63f84
commit 04b247c2eb
1 changed files with 8 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

16
arch/x86/events/intel/cqm.c
View File

@ -1682,7 +1682,7 @@ static int __init intel_cqm_init(void)
* *
* Also, check that the scales match on all cpus. * Also, check that the scales match on all cpus.
*/ */
get_online_cpus(); cpus_read_lock();
for_each_online_cpu(cpu) { for_each_online_cpu(cpu) {
struct cpuinfo_x86 *c = &cpu_data(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 * Setup the hot cpu notifier once we are sure cqm
* is enabled to avoid notifier leak. * 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", "perf/x86/cqm:starting",
intel_cqm_cpu_starting, NULL); 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,
NULL, intel_cqm_cpu_exit); "perf/x86/cqm:online",
NULL, intel_cqm_cpu_exit);
out: out:
put_online_cpus(); cpus_read_unlock();
if (ret) { if (ret) {
kfree(str); kfree(str);