On Thu, Nov 14, 2019 at 6:19 PM Madhavan Srinivasan
<ma...@linux.vnet.ibm.com> wrote:
>
> When a root user or a user with CAP_SYS_ADMIN
> privilege use trace_imc performance monitoring
> unit events, to monitor application or KVM threads,
> may result in a checkstop (System crash). Reason
> being frequent switch of the "trace/accumulation"
> mode of In-Memory Collection hardware.
> This patch disables trace_imc pmu unit, but will
> be re-enabled at a later stage with a fix patchset.
> ---
> arch/powerpc/platforms/powernv/opal-imc.c | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/arch/powerpc/platforms/powernv/opal-imc.c
> b/arch/powerpc/platforms/powernv/opal-imc.c
> index e04b20625cb9..5790f078771f 100644
> --- a/arch/powerpc/platforms/powernv/opal-imc.c
> +++ b/arch/powerpc/platforms/powernv/opal-imc.c
> @@ -285,7 +285,12 @@ static int opal_imc_counters_probe(struct
> platform_device *pdev)
> domain = IMC_DOMAIN_THREAD;
> break;
> case IMC_TYPE_TRACE:
> - domain = IMC_DOMAIN_TRACE;
> + /* Using trace_imc events to monitor
> + * application or KVM thread performances
> + * may result in a checkstop (system crash).
> + * So disabling it for now.
> + */
> + domain = -1;
> break;
> default:
> pr_warn("IMC Unknown Device type \n");
> --
> 2.21.0
>
Does this need a Fixes: tag?
