From d29859e7777ebc2c8e2db6e4d8e299f50fc26414 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Sun, 20 Mar 2016 18:59:03 +0000 Subject: [PATCH] x86/perf/intel/cstate: Sanitize error handling There is no point in WARN_ON() inside of a well known init function. We already know the call stack and it's really not of critical importance whether the registration of a PMU fails. Aside of that for consistency reasons it's just pointless to try to register another PMU if the first register attempt failed. There is also no value in keeping one PMU if the second one can not be registered. Make it consistent so we can finaly modularize the driver. Signed-off-by: Thomas Gleixner Signed-off-by: Peter Zijlstra (Intel) Cc: Alexander Shishkin Cc: Arnaldo Carvalho de Melo Cc: Borislav Petkov Cc: Jiri Olsa Cc: Kan Liang Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Stephane Eranian Cc: Vince Weaver Link: http://lkml.kernel.org/r/20160320185623.579794064@linutronix.de Signed-off-by: Ingo Molnar --- arch/x86/events/intel/cstate.c | 50 ++++++++++++++++++---------------- 1 file changed, 27 insertions(+), 23 deletions(-) diff --git a/arch/x86/events/intel/cstate.c b/arch/x86/events/intel/cstate.c index 1aac40f1e4fe..e90ec9e73ac7 100644 --- a/arch/x86/events/intel/cstate.c +++ b/arch/x86/events/intel/cstate.c @@ -581,37 +581,45 @@ static int __init cstate_probe(const struct cstate_model *cm) return (has_cstate_core || has_cstate_pkg) ? 0 : -ENODEV; } -static void __init cstate_cpumask_init(void) +static void __init cstate_cleanup(void) { - int cpu; - - cpu_notifier_register_begin(); - - for_each_online_cpu(cpu) - cstate_cpu_init(cpu); + if (has_cstate_core) + perf_pmu_unregister(&cstate_core_pmu); - __perf_cpu_notifier(cstate_cpu_notifier); - - cpu_notifier_register_done(); + if (has_cstate_pkg) + perf_pmu_unregister(&cstate_pkg_pmu); } -static void __init cstate_pmus_register(void) +static int __init cstate_init(void) { - int err; + int cpu, err; + + cpu_notifier_register_begin(); + for_each_online_cpu(cpu) + cstate_cpu_init(cpu); if (has_cstate_core) { err = perf_pmu_register(&cstate_core_pmu, cstate_core_pmu.name, -1); - if (WARN_ON(err)) - pr_info("Failed to register PMU %s error %d\n", - cstate_core_pmu.name, err); + if (err) { + has_cstate_core = false; + pr_info("Failed to register cstate core pmu\n"); + goto out; + } } if (has_cstate_pkg) { err = perf_pmu_register(&cstate_pkg_pmu, cstate_pkg_pmu.name, -1); - if (WARN_ON(err)) - pr_info("Failed to register PMU %s error %d\n", - cstate_pkg_pmu.name, err); + if (err) { + has_cstate_pkg = false; + pr_info("Failed to register cstate pkg pmu\n"); + cstate_cleanup(); + goto out; + } } + __perf_cpu_notifier(cstate_cpu_notifier); +out: + cpu_notifier_register_done(); + return err; } static int __init cstate_pmu_init(void) @@ -630,10 +638,6 @@ static int __init cstate_pmu_init(void) if (err) return err; - cstate_cpumask_init(); - - cstate_pmus_register(); - - return 0; + return cstate_init(); } device_initcall(cstate_pmu_init); -- 2.20.1