Commit-ID: 0d443b70cc92d741cbc1dcbf1079897b3d8bc3cc Gitweb: http://git.kernel.org/tip/0d443b70cc92d741cbc1dcbf1079897b3d8bc3cc Author: Mike Travis <[email protected]> AuthorDate: Tue, 7 Mar 2017 15:08:42 -0600 Committer: Thomas Gleixner <[email protected]> CommitDate: Mon, 13 Mar 2017 20:45:18 +0100
x86/platform: Remove warning message for duplicate NMI handlers Remove the WARNING message associated with multiple NMI handlers as there are at least two that are legitimate. These are the KGDB and the UV handlers and both want to be called if the NMI has not been claimed by any other NMI handler. Use of the UNKNOWN NMI call chain dramatically lowers the NMI call rate when high frequency NMI tools are in use, notably the perf tools. It is required on systems that cannot sustain a high NMI call rate without adversely affecting the system operation. Signed-off-by: Mike Travis <[email protected]> Reviewed-by: Dimitri Sivanich <[email protected]> Cc: Don Zickus <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Russ Anderson <[email protected]> Cc: Frank Ramsay <[email protected]> Cc: Tony Ernst <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Thomas Gleixner <[email protected]> --- arch/x86/kernel/nmi.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/arch/x86/kernel/nmi.c b/arch/x86/kernel/nmi.c index f088ea4..a723ae94 100644 --- a/arch/x86/kernel/nmi.c +++ b/arch/x86/kernel/nmi.c @@ -166,11 +166,9 @@ int __register_nmi_handler(unsigned int type, struct nmiaction *action) spin_lock_irqsave(&desc->lock, flags); /* - * most handlers of type NMI_UNKNOWN never return because - * they just assume the NMI is theirs. Just a sanity check - * to manage expectations + * Indicate if there are multiple registrations on the + * internal NMI handler call chains (SERR and IO_CHECK). */ - WARN_ON_ONCE(type == NMI_UNKNOWN && !list_empty(&desc->head)); WARN_ON_ONCE(type == NMI_SERR && !list_empty(&desc->head)); WARN_ON_ONCE(type == NMI_IO_CHECK && !list_empty(&desc->head));
