[tip:perf/hw-branch-sampling] perf: Disable PERF_SAMPLE_BRANCH_* when not supported

From: tip-bot for Stephane Eranian
Date: Fri Mar 09 2012 - 08:26:40 EST


Commit-ID: 2481c5fa6db0237e4f0168f88913178b2b495b7c
Gitweb: http://git.kernel.org/tip/2481c5fa6db0237e4f0168f88913178b2b495b7c
Author: Stephane Eranian <eranian@xxxxxxxxxx>
AuthorDate: Thu, 9 Feb 2012 23:20:59 +0100
Committer: Ingo Molnar <mingo@xxxxxxx>
CommitDate: Mon, 5 Mar 2012 14:55:42 +0100

perf: Disable PERF_SAMPLE_BRANCH_* when not supported

PERF_SAMPLE_BRANCH_* is disabled for:

- SW events (sw counters, tracepoints)
- HW breakpoints
- ALL but Intel x86 architecture
- AMD64 processors

Signed-off-by: Stephane Eranian <eranian@xxxxxxxxxx>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Link: http://lkml.kernel.org/r/1328826068-11713-10-git-send-email-eranian@xxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
---
arch/alpha/kernel/perf_event.c | 4 ++++
arch/arm/kernel/perf_event.c | 4 ++++
arch/mips/kernel/perf_event_mipsxx.c | 4 ++++
arch/powerpc/kernel/perf_event.c | 4 ++++
arch/sh/kernel/perf_event.c | 4 ++++
arch/sparc/kernel/perf_event.c | 4 ++++
arch/x86/kernel/cpu/perf_event_amd.c | 3 +++
kernel/events/core.c | 24 ++++++++++++++++++++++++
kernel/events/hw_breakpoint.c | 6 ++++++
9 files changed, 57 insertions(+), 0 deletions(-)

diff --git a/arch/alpha/kernel/perf_event.c b/arch/alpha/kernel/perf_event.c
index 8143cd7..0dae252 100644
--- a/arch/alpha/kernel/perf_event.c
+++ b/arch/alpha/kernel/perf_event.c
@@ -685,6 +685,10 @@ static int alpha_pmu_event_init(struct perf_event *event)
{
int err;

+ /* does not support taken branch sampling */
+ if (has_branch_stack(event))
+ return -EOPNOTSUPP;
+
switch (event->attr.type) {
case PERF_TYPE_RAW:
case PERF_TYPE_HARDWARE:
diff --git a/arch/arm/kernel/perf_event.c b/arch/arm/kernel/perf_event.c
index 5bb91bf..a23c42a 100644
--- a/arch/arm/kernel/perf_event.c
+++ b/arch/arm/kernel/perf_event.c
@@ -539,6 +539,10 @@ static int armpmu_event_init(struct perf_event *event)
int err = 0;
atomic_t *active_events = &armpmu->active_events;

+ /* does not support taken branch sampling */
+ if (has_branch_stack(event))
+ return -EOPNOTSUPP;
+
if (armpmu->map_event(event) == -ENOENT)
return -ENOENT;

diff --git a/arch/mips/kernel/perf_event_mipsxx.c b/arch/mips/kernel/perf_event_mipsxx.c
index e3b897a..811084f 100644
--- a/arch/mips/kernel/perf_event_mipsxx.c
+++ b/arch/mips/kernel/perf_event_mipsxx.c
@@ -606,6 +606,10 @@ static int mipspmu_event_init(struct perf_event *event)
{
int err = 0;

+ /* does not support taken branch sampling */
+ if (has_branch_stack(event))
+ return -EOPNOTSUPP;
+
switch (event->attr.type) {
case PERF_TYPE_RAW:
case PERF_TYPE_HARDWARE:
diff --git a/arch/powerpc/kernel/perf_event.c b/arch/powerpc/kernel/perf_event.c
index f04c230..c2e27ed 100644
--- a/arch/powerpc/kernel/perf_event.c
+++ b/arch/powerpc/kernel/perf_event.c
@@ -1084,6 +1084,10 @@ static int power_pmu_event_init(struct perf_event *event)
if (!ppmu)
return -ENOENT;

+ /* does not support taken branch sampling */
+ if (has_branch_stack(event))
+ return -EOPNOTSUPP;
+
switch (event->attr.type) {
case PERF_TYPE_HARDWARE:
ev = event->attr.config;
diff --git a/arch/sh/kernel/perf_event.c b/arch/sh/kernel/perf_event.c
index 10b14e3..068b8a2 100644
--- a/arch/sh/kernel/perf_event.c
+++ b/arch/sh/kernel/perf_event.c
@@ -310,6 +310,10 @@ static int sh_pmu_event_init(struct perf_event *event)
{
int err;

+ /* does not support taken branch sampling */
+ if (has_branch_stack(event))
+ return -EOPNOTSUPP;
+
switch (event->attr.type) {
case PERF_TYPE_RAW:
case PERF_TYPE_HW_CACHE:
diff --git a/arch/sparc/kernel/perf_event.c b/arch/sparc/kernel/perf_event.c
index 614da62..8e16a4a 100644
--- a/arch/sparc/kernel/perf_event.c
+++ b/arch/sparc/kernel/perf_event.c
@@ -1105,6 +1105,10 @@ static int sparc_pmu_event_init(struct perf_event *event)
if (atomic_read(&nmi_active) < 0)
return -ENODEV;

+ /* does not support taken branch sampling */
+ if (has_branch_stack(event))
+ return -EOPNOTSUPP;
+
switch (attr->type) {
case PERF_TYPE_HARDWARE:
if (attr->config >= sparc_pmu->max_events)
diff --git a/arch/x86/kernel/cpu/perf_event_amd.c b/arch/x86/kernel/cpu/perf_event_amd.c
index 67250a5..dd002fa 100644
--- a/arch/x86/kernel/cpu/perf_event_amd.c
+++ b/arch/x86/kernel/cpu/perf_event_amd.c
@@ -139,6 +139,9 @@ static int amd_pmu_hw_config(struct perf_event *event)
if (ret)
return ret;

+ if (has_branch_stack(event))
+ return -EOPNOTSUPP;
+
if (event->attr.exclude_host && event->attr.exclude_guest)
/*
* When HO == GO == 1 the hardware treats that as GO == HO == 0
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 5820efd..242bb51 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -5044,6 +5044,12 @@ static int perf_swevent_init(struct perf_event *event)
if (event->attr.type != PERF_TYPE_SOFTWARE)
return -ENOENT;

+ /*
+ * no branch sampling for software events
+ */
+ if (has_branch_stack(event))
+ return -EOPNOTSUPP;
+
switch (event_id) {
case PERF_COUNT_SW_CPU_CLOCK:
case PERF_COUNT_SW_TASK_CLOCK:
@@ -5154,6 +5160,12 @@ static int perf_tp_event_init(struct perf_event *event)
if (event->attr.type != PERF_TYPE_TRACEPOINT)
return -ENOENT;

+ /*
+ * no branch sampling for tracepoint events
+ */
+ if (has_branch_stack(event))
+ return -EOPNOTSUPP;
+
err = perf_trace_init(event);
if (err)
return err;
@@ -5379,6 +5391,12 @@ static int cpu_clock_event_init(struct perf_event *event)
if (event->attr.config != PERF_COUNT_SW_CPU_CLOCK)
return -ENOENT;

+ /*
+ * no branch sampling for software events
+ */
+ if (has_branch_stack(event))
+ return -EOPNOTSUPP;
+
perf_swevent_init_hrtimer(event);

return 0;
@@ -5453,6 +5471,12 @@ static int task_clock_event_init(struct perf_event *event)
if (event->attr.config != PERF_COUNT_SW_TASK_CLOCK)
return -ENOENT;

+ /*
+ * no branch sampling for software events
+ */
+ if (has_branch_stack(event))
+ return -EOPNOTSUPP;
+
perf_swevent_init_hrtimer(event);

return 0;
diff --git a/kernel/events/hw_breakpoint.c b/kernel/events/hw_breakpoint.c
index 3330022..bb38c4d 100644
--- a/kernel/events/hw_breakpoint.c
+++ b/kernel/events/hw_breakpoint.c
@@ -581,6 +581,12 @@ static int hw_breakpoint_event_init(struct perf_event *bp)
if (bp->attr.type != PERF_TYPE_BREAKPOINT)
return -ENOENT;

+ /*
+ * no branch sampling for breakpoint events
+ */
+ if (has_branch_stack(bp))
+ return -EOPNOTSUPP;
+
err = register_perf_hw_breakpoint(bp);
if (err)
return err;
--
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