From 94f4db3590893c600506105b88dab581c7f6f5c8 Mon Sep 17 00:00:00 2001 From: Jacob Shin Date: Sun, 21 Apr 2013 13:06:27 -0500 Subject: [PATCH] perf/x86/amd: Fix AMD NB and L2I "uncore" support Borislav Petkov reported a lockdep splat warning about kzalloc() done in an IPI (hardirq) handler. This is a real bug, do not call kzalloc() in a smp_call_function_single() handler because it can schedule and crash. Reported-by: Borislav Petkov Signed-off-by: Jacob Shin Tested-by: Borislav Petkov Cc: Borislav Petkov Cc: Cc: Cc: Cc: Link: http://lkml.kernel.org/r/20130421180627.GA21049@jshin-Toonie Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/perf_event_amd_uncore.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/arch/x86/kernel/cpu/perf_event_amd_uncore.c b/arch/x86/kernel/cpu/perf_event_amd_uncore.c index 6dc62273639c..c0c661adf03e 100644 --- a/arch/x86/kernel/cpu/perf_event_amd_uncore.c +++ b/arch/x86/kernel/cpu/perf_event_amd_uncore.c @@ -498,7 +498,6 @@ static void __init init_cpu_already_online(void *dummy) { unsigned int cpu = smp_processor_id(); - amd_uncore_cpu_up_prepare(cpu); amd_uncore_cpu_starting(cpu); amd_uncore_cpu_online(cpu); } @@ -535,8 +534,10 @@ static int __init amd_uncore_init(void) get_online_cpus(); /* init cpus already online before registering for hotplug notifier */ - for_each_online_cpu(cpu) + for_each_online_cpu(cpu) { + amd_uncore_cpu_up_prepare(cpu); smp_call_function_single(cpu, init_cpu_already_online, NULL, 1); + } register_cpu_notifier(&amd_uncore_cpu_notifier_block); put_online_cpus();