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authorAnju T Sudhakar <anju@linux.vnet.ibm.com>2020-03-13 06:52:38 +0100
committerMichael Ellerman <mpe@ellerman.id.au>2020-04-02 15:09:58 +0200
commit4bdd39460b5f57d4f165c4a05b22e66eb3a490ae (patch)
tree9bb3acae471d388348459679d43adafbbac7e938 /arch/powerpc
parentpowerpc/perf: Implement a global lock to avoid races between trace, core and ... (diff)
downloadlinux-4bdd39460b5f57d4f165c4a05b22e66eb3a490ae.tar.xz
linux-4bdd39460b5f57d4f165c4a05b22e66eb3a490ae.zip
powerpc/powernv: Re-enable imc trace-mode in kernel
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 previous patch(1/2) 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. Signed-off-by: Anju T Sudhakar <anju@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200313055238.8656-2-anju@linux.vnet.ibm.com
Diffstat (limited to 'arch/powerpc')
-rw-r--r--arch/powerpc/platforms/powernv/opal-imc.c9
1 files changed, 1 insertions, 8 deletions
diff --git a/arch/powerpc/platforms/powernv/opal-imc.c b/arch/powerpc/platforms/powernv/opal-imc.c
index 968b9a4d1cd9..7824cc364bc4 100644
--- a/arch/powerpc/platforms/powernv/opal-imc.c
+++ b/arch/powerpc/platforms/powernv/opal-imc.c
@@ -268,14 +268,7 @@ 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");