On 1/21/20 3:47 PM, Anju T Sudhakar wrote:
commit <249fad734a25> ""powerpc/perf: Disable trace_imc pmu"
disables IMC(In-Memory Collection) trace-mode in kernel, since frequent
mode switching between accumulation mode and trace mode via the spr LDBAR
in the hardware can trigger a checkstop(system crash).
Patch to re-enable imc-trace mode in kernel.
The following patch in this series will address the mode switching issue
by implementing a global lock, and will restrict the usage of
accumulation and trace-mode at a time.
Reviewed-by: MAdhavan Srinivasan <ma...@linux.ibm.com>
Signed-off-by: Anju T Sudhakar <a...@linux.vnet.ibm.com>
---
arch/powerpc/platforms/powernv/opal-imc.c | 9 +--------
1 file changed, 1 insertion(+), 8 deletions(-)
diff --git a/arch/powerpc/platforms/powernv/opal-imc.c
b/arch/powerpc/platforms/powernv/opal-imc.c
index 000b350d4060..3b4518f4b643 100644
--- a/arch/powerpc/platforms/powernv/opal-imc.c
+++ b/arch/powerpc/platforms/powernv/opal-imc.c
@@ -278,14 +278,7 @@ static int opal_imc_counters_probe(struct platform_device
*pdev)
domain = IMC_DOMAIN_THREAD;
break;
case IMC_TYPE_TRACE:
- /*
- * FIXME. Using trace_imc events to monitor application
- * or KVM thread performance can cause a checkstop
- * (system crash).
- * Disable it for now.
- */
- pr_info_once("IMC: disabling trace_imc PMU\n");
- domain = -1;
+ domain = IMC_DOMAIN_TRACE;
break;
default:
pr_warn("IMC Unknown Device type \n");
