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powerpc/perf/hv-24x7: Aggregate result elements on POWER9 SMT8

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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.

Reviewed-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit is contained in:
Thiago Jung Bauermann 2017-06-29 18:55:38 -03:00 committed by Michael Ellerman
parent 2e6553aae3
commit bfaa7834b6
1 changed files with 42 additions and 11 deletions
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53
arch/powerpc/perf/hv-24x7.c
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@ -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))
@ -1145,17 +1157,23 @@ 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.
@ -1172,6 +1190,8 @@ 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 i;
u64 count;
/*
* We can bail out early if the result is empty.
@ -1189,8 +1209,10 @@ static int get_count_from_result(struct perf_event *event,
/*
* Since we always specify 1 as the maximum for the smallest resource
* we're requesting, there should to be only one element per result.
* Except when an event needs aggregation, in which case there are more.
*/
if (num_elements != 1) {
if (num_elements != 1 &&
!domain_needs_aggregation(event_get_domain(event))) {
pr_err("Error: result of request %hhu has %hu elements\n",
res->result_ix, num_elements);
@ -1211,13 +1233,17 @@ 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)
count += be64_to_cpu(*((u64 *) element_data));
*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 0;
}
@ -1568,9 +1594,14 @@ static int hv_24x7_init(void)
/* POWER8 only supports v1, while POWER9 only supports v2. */
if (!strcmp(cur_cpu_spec->oprofile_cpu_type, "ppc64/power8"))
interface_version = 1;
else
else {
interface_version = 2;
/* SMT8 in POWER9 needs to aggregate result elements. */
if (threads_per_core == 8)
aggregate_result_elements = true;
}
hret = hv_perf_caps_get(&caps);
if (hret) {
pr_debug("could not obtain capabilities, not enabling, rc=%ld\n",