[PATCH v6 01/18] perf, x86: Support CPU specific sysfs events

Stephane Eranian
2013-01-15T15:48:58Z

From: Andi Kleen <ak@linux.intel.com>

Add a way for the CPU initialization code to register additional events,
and merge them into the events attribute directory. Used in the next
patch.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
---
arch/x86/kernel/cpu/perf_event.c | 33 +++++++++++++++++++++++++++++++++
arch/x86/kernel/cpu/perf_event.h | 1 +
2 files changed, 34 insertions(+)

diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index 4428fd1..26df58b 100644
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -1341,6 +1341,30 @@ static void __init filter_events(struct attribute **attrs)
}
}

+/* Merge two pointer arrays */
+static __init struct attribute **merge_attr(struct attribute **a,
+ struct attribute **b)
+{
+ struct attribute **new;
+ int j, i;
+
+ for (j = 0; a[j]; j++)
+ ;
+ for (i = 0; b[i]; i++)
+ j++;
+ j++;
+ new = kmalloc(sizeof(struct attribute *) * j, GFP_KERNEL);
+ if (!new)
+ return NULL;
+ j = 0;
+ for (i = 0; a[i]; i++)
+ new[j++] = a[i];
+ for (i = 0; b[i]; i++)
+ new[j++] = b[i];
+ new[j] = NULL;
+ return new;
+}
+
static ssize_t events_sysfs_show(struct device *dev, struct device_attribute *attr,
char *page)
{
@@ -1482,6 +1506,15 @@ static int __init init_hw_perf_events(void)
else
filter_events(x86_pmu_events_group.attrs);

+ if (x86_pmu.cpu_events) {
+ struct attribute *tmp;
+
+ tmp = merge_attr(x86_pmu_events_group.attrs,
+ x86_pmu.cpu_events);
+ if (!WARN_ON(!tmp))
+ x86_pmu_events_group.attrs = tmp;
+ }
+
pr_info("... version: %d\n", x86_pmu.version);
pr_info("... bit width: %d\n", x86_pmu.cntval_bits);
pr_info("... generic registers: %d\n", x86_pmu.num_counters);
diff --git a/arch/x86/kernel/cpu/perf_event.h b/arch/x86/kernel/cpu/perf_event.h
index 115c1ea..4170043 100644
--- a/arch/x86/kernel/cpu/perf_event.h
+++ b/arch/x86/kernel/cpu/perf_event.h
@@ -355,6 +355,7 @@ struct x86_pmu {
struct attribute **format_attrs;

ssize_t (*events_sysfs_show)(char *page, u64 config);
+ struct attribute **cpu_events;

/*
* CPU Hotplug hooks
--
1.7.9.5