diff options
Diffstat (limited to 'patches/0013-perf-x86-intel-cqm-Use-cpuhp_setup_state_cpuslocked.patch')
| -rw-r--r-- | patches/0013-perf-x86-intel-cqm-Use-cpuhp_setup_state_cpuslocked.patch | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/patches/0013-perf-x86-intel-cqm-Use-cpuhp_setup_state_cpuslocked.patch b/patches/0013-perf-x86-intel-cqm-Use-cpuhp_setup_state_cpuslocked.patch new file mode 100644 index 000000000000..883a08ddb171 --- /dev/null +++ b/patches/0013-perf-x86-intel-cqm-Use-cpuhp_setup_state_cpuslocked.patch @@ -0,0 +1,64 @@ +From 04b247c2ebdd6ba1c46c7c22546229a89760b43a Mon Sep 17 00:00:00 2001 +From: Sebastian Andrzej Siewior <bigeasy@linutronix.de> +Date: Wed, 24 May 2017 10:15:24 +0200 +Subject: [PATCH 13/32] 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@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 +--- + 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 8c00dc09a5d2..2521f771f2f5 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); +-- +2.11.0 + |