tools/testing/selftests/powerpc/pmu/per_event_excludes.c

Source file repositories/reference/linux-study-clean/tools/testing/selftests/powerpc/pmu/per_event_excludes.c

File Facts

System
Linux kernel
Corpus path
tools/testing/selftests/powerpc/pmu/per_event_excludes.c
Extension
.c
Size
2603 bytes
Lines
112
Domain
Support Tooling And Documentation
Bucket
tools
Inferred role
Support Tooling And Documentation: implementation source
Status
source implementation candidate

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright 2014, Michael Ellerman, IBM Corp.
 */

#define _GNU_SOURCE

#include <elf.h>
#include <limits.h>
#include <stdio.h>
#include <stdbool.h>
#include <string.h>
#include <sys/prctl.h>

#include "event.h"
#include "lib.h"
#include "utils.h"

/*
 * Test that per-event excludes work.
 */

static int per_event_excludes(void)
{
	struct event *e, events[4];
	int i;

	SKIP_IF(!have_hwcap2(PPC_FEATURE2_ARCH_2_07));

	/*
	 * We need to create the events disabled, otherwise the running/enabled
	 * counts don't match up.
	 */
	e = &events[0];
	event_init_opts(e, PERF_COUNT_HW_INSTRUCTIONS,
			PERF_TYPE_HARDWARE, "instructions");
	e->attr.disabled = 1;

	e = &events[1];
	event_init_opts(e, PERF_COUNT_HW_INSTRUCTIONS,
			PERF_TYPE_HARDWARE, "instructions(k)");
	e->attr.disabled = 1;
	e->attr.exclude_user = 1;
	e->attr.exclude_hv = 1;

	e = &events[2];
	event_init_opts(e, PERF_COUNT_HW_INSTRUCTIONS,
			PERF_TYPE_HARDWARE, "instructions(h)");
	e->attr.disabled = 1;
	e->attr.exclude_user = 1;
	e->attr.exclude_kernel = 1;

	e = &events[3];
	event_init_opts(e, PERF_COUNT_HW_INSTRUCTIONS,
			PERF_TYPE_HARDWARE, "instructions(u)");
	e->attr.disabled = 1;
	e->attr.exclude_hv = 1;
	e->attr.exclude_kernel = 1;

	FAIL_IF(event_open(&events[0]));

	/*
	 * The open here will fail if we don't have per event exclude support,
	 * because the second event has an incompatible set of exclude settings
	 * and we're asking for the events to be in a group.
	 */
	for (i = 1; i < 4; i++)
		FAIL_IF(event_open_with_group(&events[i], events[0].fd));

	/*
	 * Even though the above will fail without per-event excludes we keep
	 * testing in order to be thorough.
	 */
	prctl(PR_TASK_PERF_EVENTS_ENABLE);

	/* Spin for a while */
	for (i = 0; i < INT_MAX; i++)
		asm volatile("" : : : "memory");

	prctl(PR_TASK_PERF_EVENTS_DISABLE);

	for (i = 0; i < 4; i++) {
		FAIL_IF(event_read(&events[i]));
		event_report(&events[i]);
	}

	/*
	 * We should see that all events have enabled == running. That
	 * shows that they were all on the PMU at once.
	 */

Annotation

Implementation Notes