[tip:perf/core] perf/x86/amd/iommu: Do not register a task ctx for uncore like PMUs

[tip-bot for Peter Zijlstra]

Commit-ID:  8482716b9d865db34c55d4bf2fed19498e7195b9
Gitweb:     http://git.kernel.org/tip/8482716b9d865db34c55d4bf2fed19498e7195b9
Author:     Peter Zijlstra <peterz@xxxxxxxxxxxxx>
AuthorDate: Sun, 24 Apr 2016 00:42:55 +0200
Committer:  Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Thu, 5 May 2016 10:11:28 +0200

perf/x86/amd/iommu: Do not register a task ctx for uncore like PMUs

The new sanity check introduced by:

  26657848502b ("perf/core: Verify we have a single perf_hw_context PMU")

... triggered on the AMD IOMMU driver.

IOMMUs are not per logical CPU, they cannot have per-task counters. Fix it.

Reported-by: Borislav Petkov <bp@xxxxxxxxx>
Tested-by: Borislav Petkov <bp@xxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Stephane Eranian <eranian@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Vince Weaver <vincent.weaver@xxxxxxxxx>
Cc: jroedel@xxxxxxx
Cc: suravee.suthikulpanit@xxxxxxx
Link: http://lkml.kernel.org/r/20160423224255.GB3430@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
 arch/x86/events/amd/iommu.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/x86/events/amd/iommu.c b/arch/x86/events/amd/iommu.c
index 40625ca..6011a57 100644
--- a/arch/x86/events/amd/iommu.c
+++ b/arch/x86/events/amd/iommu.c
@@ -474,6 +474,7 @@ static __init int _init_perf_amd_iommu(
 
 static struct perf_amd_iommu __perf_iommu = {
 	.pmu = {
+		.task_ctx_nr    = perf_invalid_context,
 		.event_init	= perf_iommu_event_init,
 		.add		= perf_iommu_add,
 		.del		= perf_iommu_del,