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Commit 94f4db35 authored by Jacob Shin's avatar Jacob Shin Committed by Ingo Molnar
Browse files

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: default avatarBorislav Petkov <bp@suse.de>
Signed-off-by: default avatarJacob Shin <jacob.shin@amd.com>
Tested-by: default avatarBorislav Petkov <bp@suse.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: <eranian@google.com>
Cc: <a.p.zijlstra@chello.nl>
Cc: <acme@ghostprotocols.net>
Cc: <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/20130421180627.GA21049@jshin-Toonie


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 0cf5f432

arch/x86/kernel/cpu/perf_event_amd_uncore.c

+3 −2
Original line number Diff line number Diff line
@@ -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();