On POWER9 SMT8 the 24x7 API returns two result elements for physical core
and virtual CPU events and we need to add their counts to get the final
result.
Signed-off-by: Thiago Jung Bauermann <bauer...@linux.vnet.ibm.com>
---
arch/powerpc/perf/hv-24x7.c | 58 ++++++++++++++++++++++++++++++++++-----------
1 file changed, 44 insertions(+), 14 deletions(-)
diff --git a/arch/powerpc/perf/hv-24x7.c b/arch/powerpc/perf/hv-24x7.c
index 95c44f1d2fd2..641f385e7eb0 100644
--- a/arch/powerpc/perf/hv-24x7.c
+++ b/arch/powerpc/perf/hv-24x7.c
@@ -31,6 +31,9 @@
/* Version of the 24x7 hypervisor API that we should use in this machine. */
static int interface_version;
+/* Whether we have to aggregate result data for some domains. */
+static bool aggregate_result_elements;
+
static bool domain_is_valid(unsigned domain)
{
switch (domain) {
@@ -58,6 +61,15 @@ static bool is_physical_domain(unsigned domain)
}
}
+/* Domains for which more than one result element are returned for each event.
*/
+static bool domain_needs_aggregation(unsigned int domain)
+{
+ return aggregate_result_elements &&
+ (domain == HV_PERF_DOMAIN_PHYS_CORE ||
+ (domain >= HV_PERF_DOMAIN_VCPU_HOME_CORE &&
+ domain <= HV_PERF_DOMAIN_VCPU_REMOTE_NODE));
+}
+
static const char *domain_name(unsigned domain)
{
if (!domain_is_valid(domain))
@@ -1149,17 +1161,23 @@ static int add_event_to_24x7_request(struct perf_event
*event,
req->starting_ix = cpu_to_be16(idx);
req->max_ix = cpu_to_be16(1);
- if (request_buffer->interface_version > 1 &&
- req->performance_domain != HV_PERF_DOMAIN_PHYS_CHIP) {
- req->starting_thread_group_ix = idx % 2;
- req->max_num_thread_groups = 1;
+ if (request_buffer->interface_version > 1) {
+ if (domain_needs_aggregation(req->performance_domain))
+ req->max_num_thread_groups = -1;
+ else if (req->performance_domain != HV_PERF_DOMAIN_PHYS_CHIP) {
+ req->starting_thread_group_ix = idx % 2;
+ req->max_num_thread_groups = 1;
+ }
}
return 0;
}
/**
- * get_count_from_result - get event count from the given result
+ * get_count_from_result - get event count from all result elements in result
+ *
+ * If the event corresponding to this result needs aggregation of the result
+ * element values, then this function does that.
*
* @event: Event associated with @res.
* @resb: Result buffer containing @res.
@@ -1176,7 +1194,8 @@ static int get_count_from_result(struct perf_event *event,
u16 data_size = be16_to_cpu(res->result_element_data_size);
unsigned int data_offset;
void *element_data;
- int ret = 0;
+ int i, ret = 0;
+ u64 count;
/*
* We can bail out early if the result is empty.
@@ -1192,9 +1211,11 @@ static int get_count_from_result(struct perf_event
*event,
}
/*
- * This code assumes that a result has only one element.
+ * This code assumes that a result has only one element, except
+ * when an event needs aggregation.
*/
- if (num_elements != 1) {
+ if (num_elements != 1 &&
+ !domain_needs_aggregation(event_get_domain(event))) {
pr_debug("Error: result of request %hhu has %hu elements\n",
res->result_ix, num_elements);
@@ -1225,14 +1246,19 @@ static int get_count_from_result(struct perf_event
*event,
data_offset = offsetof(struct hv_24x7_result_element_v2,
element_data);
- element_data = res->elements + data_offset;
+ /* Go through the result elements in the result. */
+ for (i = count = 0, element_data = res->elements + data_offset;
+ i < num_elements;
+ i++, element_data += data_size + data_offset)
+ if (!ret)
+ count += be64_to_cpu(*((u64 *) element_data));
if (!ret)
- *countp = be64_to_cpu(*((u64 *) element_data));
+ *countp = count;
- /* The next result is after the result element. */
+ /* The next result is after the last result element. */
if (next)
- *next = element_data + data_size;
+ *next = element_data - data_offset;
return ret;
}
@@ -1580,9 +1606,13 @@ static int hv_24x7_init(void)
}
/* POWER8 only supports v1, while POWER9 only supports v2. */
- if (cpu_has_feature(CPU_FTR_ARCH_300))
+ if (cpu_has_feature(CPU_FTR_ARCH_300)) {
interface_version = 2;
- else
+
+ /* SMT8 in POWER9 needs to aggregate result elements. */
+ if (threads_per_core == 8)
+ aggregate_result_elements = true;
+ } else
interface_version = 1;
hret = hv_perf_caps_get(&caps);
--
2.7.4
