129 lines
		
	
	
		
			2.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			129 lines
		
	
	
		
			2.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
// SPDX-License-Identifier: GPL-2.0
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#include "tests/tests.h"
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#include "cloexec.h"
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#include "debug.h"
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#include "evlist.h"
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#include "evsel.h"
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#include "arch-tests.h"
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#include <internal/lib.h> // page_size
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#include <signal.h>
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#include <sys/mman.h>
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#include <sys/wait.h>
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#include <errno.h>
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#include <string.h>
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static pid_t spawn(void)
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{
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	pid_t pid;
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	pid = fork();
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	if (pid)
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		return pid;
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	while(1)
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		sleep(5);
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	return 0;
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}
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/*
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 * Create an event group that contains both a sampled hardware
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 * (cpu-cycles) and software (intel_cqm/llc_occupancy/) event. We then
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 * wait for the hardware perf counter to overflow and generate a PMI,
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 * which triggers an event read for both of the events in the group.
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 *
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 * Since reading Intel CQM event counters requires sending SMP IPIs, the
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 * CQM pmu needs to handle the above situation gracefully, and return
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 * the last read counter value to avoid triggering a WARN_ON_ONCE() in
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 * smp_call_function_many() caused by sending IPIs from NMI context.
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 */
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int test__intel_cqm_count_nmi_context(struct test_suite *test __maybe_unused, int subtest __maybe_unused)
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{
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	struct evlist *evlist = NULL;
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	struct evsel *evsel = NULL;
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	struct perf_event_attr pe;
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	int i, fd[2], flag, ret;
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	size_t mmap_len;
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	void *event;
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	pid_t pid;
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	int err = TEST_FAIL;
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	flag = perf_event_open_cloexec_flag();
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	evlist = evlist__new();
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	if (!evlist) {
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		pr_debug("evlist__new failed\n");
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		return TEST_FAIL;
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	}
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	ret = parse_event(evlist, "intel_cqm/llc_occupancy/");
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	if (ret) {
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		pr_debug("parse_events failed, is \"intel_cqm/llc_occupancy/\" available?\n");
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		err = TEST_SKIP;
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		goto out;
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	}
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	evsel = evlist__first(evlist);
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	if (!evsel) {
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		pr_debug("evlist__first failed\n");
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		goto out;
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	}
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	memset(&pe, 0, sizeof(pe));
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	pe.size = sizeof(pe);
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	pe.type = PERF_TYPE_HARDWARE;
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	pe.config = PERF_COUNT_HW_CPU_CYCLES;
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	pe.read_format = PERF_FORMAT_GROUP;
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	pe.sample_period = 128;
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	pe.sample_type = PERF_SAMPLE_IP | PERF_SAMPLE_READ;
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	pid = spawn();
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	fd[0] = sys_perf_event_open(&pe, pid, -1, -1, flag);
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	if (fd[0] < 0) {
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		pr_debug("failed to open event\n");
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		goto out;
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	}
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	memset(&pe, 0, sizeof(pe));
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	pe.size = sizeof(pe);
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	pe.type = evsel->attr.type;
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	pe.config = evsel->attr.config;
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	fd[1] = sys_perf_event_open(&pe, pid, -1, fd[0], flag);
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	if (fd[1] < 0) {
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		pr_debug("failed to open event\n");
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		goto out;
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	}
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	/*
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	 * Pick a power-of-two number of pages + 1 for the meta-data
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	 * page (struct perf_event_mmap_page). See tools/perf/design.txt.
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	 */
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	mmap_len = page_size * 65;
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	event = mmap(NULL, mmap_len, PROT_READ, MAP_SHARED, fd[0], 0);
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	if (event == (void *)(-1)) {
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		pr_debug("failed to mmap %d\n", errno);
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		goto out;
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	}
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	sleep(1);
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	err = TEST_OK;
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	munmap(event, mmap_len);
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	for (i = 0; i < 2; i++)
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		close(fd[i]);
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	kill(pid, SIGKILL);
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	wait(NULL);
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out:
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	evlist__delete(evlist);
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	return err;
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}
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